Engineering_Solutions_12.0_Tutorials

Engineering Solutions 12.0 Tutorials

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Engineering Solutions 12.0 Tutorials iAltair Engineering

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Engineering Solutions 12.0 Tutorials

........................................................................................................................................... 1Engineering Solutions Tutorials

............................................................................................................................................... 3CFD

................................................................................................................................... 4CFD-1000: Creating a Hybrid Grid using the CFD Mesh Panel

................................................................................................................................... 16CFD-1100: Creating a Hybrid Grid with Varying Boundary Layer Thickness

................................................................................................................................... 23CFD-1200: CFD Meshing with Automatic BL Thickness Reduction

................................................................................................................................... 33CFD-1300: Plane 2-D Meshing with Boundary Layers

................................................................................................................................... 45CFD-1400: Wind Tunnel Mesh

................................................................................................................................... 60CFD-1500: Hexcore Meshing with Boundary Layer

................................................................................................................................... 69CFD-1600: Using Distributed Thickness for Varying Boundary Layer Thickness

................................................................................................................................... 80CFD-1700: Mapping CFD Results

................................................................................................................................... 86CFD-1800: Using HyperMesh, AcuSolve and HyperView to Perform a CFD Analysis

............................................................................................................................................... 105Crash

................................................................................................................................... 106CRASH-1000: Defining LS-DYNA Model and Load Data, Controls, and Output

................................................................................................................................... 119CRASH-1100: Using Curves, Beams, Rigid Bodies Joints, and Loads in LS-DYNA

................................................................................................................................... 134

CRASH-1200: Model Importing, Airbags, Exporting Displayed, and Contacts usingDYNA

................................................................................................................................... 143CRASH-1300: Rigid Wall, Model Data, Constraints, and Output using DYNA

................................................................................................................................... 153CRASH-2000: Front Impact Bumper Model

................................................................................................................................... 169CRASH-2100: Simplified Car Pole Impact

............................................................................................................................................... 183NVH

................................................................................................................................... 185NVH-1000: Acoustic Cavity

................................................................................................................................... 201NVH-1100: NVH Director Assembly

Altair Engineering Engineering Solutions 12.0 Tutorials 1


Engineering Solutions Tutorials

File Location Most tutorials use files that are located in the tutorials\

directory of the software installation. In the tutorials, file pathsare referenced as <install_directory>\..\.

Finding the InstallationDirectory

In order to locate the files needed, you will need to determinethe path of the installation directory <install_directory>. This

path is dependent on the installation that was performed at yoursite. To determine what this path is, follow these instructions:

1. Launch the application.

2. From the Help menu, select Updates and SystemInform ation.

The HyperWorks Updates and System Information dialogopens. The installation directory path appears after AltairHome:.

The tutorial model files are located in <install_directory>\tutorials\es\.

Downloading ModelFiles

If you are using the tutorials via the Altair website, you will needto download the model files before beginning. Access them byclicking:

http://www.altairhyperworks.com/hwhelp/Altair/hw12.0/index.aspx

Please note that a User ID and password is required to accessthis area. Follow the instructions provided to obtain the logininformation.

See the full listing of available tutorials:

CFD User Profile Tutorials

Crash User Profile Tutorials

NVH User Profile Tutorials





CFD

The following tutorials are available for the CFD user profile:

CFD-1000: Creating a Hybrid Grid using the CFD Mesh Panel

CFD-1100: Creating a Hybrid Grid with Varying Boundary Layer Thickness

CFD-1200: CFD Meshing with Automatic BL Thickness Reduction

CFD-1300: Plane 2-D Meshing with Boundary Layers

CFD-1400: Wind Tunnel Mesh

CFD-1500: Hexcore Meshing with Boundary Layer

CFD-1600: Using Distributed Thickness for Varying Boundary Layer Thickness

CFD-1700:Mapping CFD Results

CFD-1800:Using HyperMesh, AcuSolve and HyperView to perform a CFD analysis

Engineering Solutions 12.0 Tutorials4 Altair Engineering


CFD-1000: Creating a Hybrid Grid using the CFD MeshPanel

In this tutorial, you will learn to:

Generate meshes for CFD applications (for example Fluent, StarCD) using the CFDTetramesh panel

Generate boundary layer type meshes with an arbitrary number of layers and thicknessdistribution

Specify/identify boundary regions for CFD simulations

Export a mesh with boundary regions for FLUENT

Import the model into FLUENT

Exercise

Step 1: Open the model file

1. From the toolbar, click Open Model .

2. Select the manifold_surf_mesh.hm file from the tutorial directory.

3. Click Open to load this .hm file containing the surface mesh.

Step 2: Load the CFD user profile

1. Click Preferences > User Profiles.

2. In the Application field, select Engineering Solutions.



3. Select the radio button C FD and select AcuSolve from the drop down menu.

4. Click OK.

5. Inspect the surface elements that will be used to generate the volume mesh.

The boundary mesh can have any combination of tria/quad elements. You will generateboundary layers on all the surface elements contained in the collector named wall.

Step 3: Check that all the elements in the collectors wall, inlet, andoutlets define a closed volume

1. Click Mesh > C heck > C om ponent > Edges to open the Edges panel.

2. Click the yellow com ps button and select the collectors wall, inlet and outlets.

3. Click se lect, and then c lick find edges.

A message indicating that no edges were found will appear on the status bar.

4. Toggle the free edges button to T-connections.

5. Select the three components again and then click find edges.

The status bar will display: "No T -c onnec ted edges w ere found."

6. Click return to close the panel.

Step 4: Create the CFD mesh

1. Click Mesh > Volum e Mesh 3D > C FD tetram esh to open the CFD Tetramesh panel.

2. Click the Boundary se lection subpanel.

You will need to first select all the elements/components that define the surface area onwhich you need to generate boundary layers. This is done by selecting the elements/components under the With BL (float) and With BL (fixed) selectors.

3. Under the heading With BL (fixed), click com ps and select the collector wall.

Next, select the remaining elements/components which define the volume but where aboundary layer is not desired. This is done by selecting the elements/components underthe W/o BL (float) and W/o BL (fixed) selectors.

4. Under the heading W/o BL (float), click com ps and select the collectors inlet andoutlets.

5. Verify that the switch below the W/o BL (float) selector is set to Remesh. This meansthat the meshes in the zones defined by collectors inlet and outlets will be remeshedafter being deformed by the boundary layer growth from adjacent surface areas.

6. Leave the default Smooth BL option unchanged.

This option is strongly recommended for most cases because it produces boundary layerswith more uniform thickness and better element quality.



7. Click the BL param eters subpanel. All the data that has been entered in the Boundaryselection subpanel is stored.

8. Select the options to specify the boundary layer and tetrahedral core:

Number of Layers = 5

First layer thickness = 0.5

BL growth rate= 1.1 (This non-dimensional factor controls the change in layerthickness from one layer to the next).

9. Under the BL hexa transition mode header, verify that selection is set to SimplePyramid.

The default, Simple Pyramid, uses one pyramid element to transition from a BLhexahedral’s quad face to the tetrahedral core mesh.

10. Leave the BL only checkbox unchecked.

This option generates the boundary layer alone and stops before generating thetetrahedral core. This option modifies adjacent surface meshes to reflect changesintroduced by the boundary layer thickness, and creates a collector named ^CFD_trias_for_tetramesh, that is used to generate the inner core tetrahedral meshusing the Tetramesh parameters subpanel.

11. Click the Tetram esh param eters subpanel.

12. There are three different tetrameshing algorithms available. Select Optim ize MeshQuality.

For a detailed explanation of each option, please refer to the online help.

13. Set the tetrahedral core growth rate to Interpolate.

This avoids the problem of generating tetrahedral elements that are too large at thecenter of the core mesh.

14. Click m esh to create the CFD mesh.

When this task is finished, two collectors are automatically created: CFD_bl001 andCFD_tetcore001.



.


Step 5: Mask some of the mesh to view the interior elements andboundary layers

1. You can mask the mesh by using the shortcut key F5, and select elements to be masked.

Following is a snapshot. Observe the excellent mesh quality produced.

2. You can also use the Hidden Line panel to view the interior of a solid mesh. Click BC s >C heck > H idden Lines to access the panel.

3. Leave the title field blank and check the option for yz plane.

This defines the yz plane as the cutting plane.

4. Leave the options for trim planes and clip boundary elements checked on and clickshow plot.

This automatically places the cutting plane at the center of the model. Notice that thedisplay of the elements has been collapsed so that the nodes lie on the cutting plane.



5. Left-click in the graphics area where the cutting plane is, hold down the left mousebutton, and drag the mouse. Notice that the cutting plane moves.

6. Next, uncheck the option for clip boundary elements and click show plot.

Notice how the elements are displayed completely.

7. Drag the placement of the cutting plane. Experiment with the other cutting planes andthe trim planes option to see how they affect the plot.

8. Click return to exit the panel and clear the plot.

Step 6: Organize the model

In this section, you will define mesh surface regions used to specify boundary conditions inany CFD code ( FLUENT, StarCD, CFX, etc). For example, assume that you are going toexport the mesh for FLUENT. For this model, you need to create three collectors to place theboundaries: inflow, outflow, and wall. You have selected two new names that are notalready in your database and at the same time are compatible with the prefixes required byFLUENT to recognize boundary types according to their names.

You are going to reuse the surface mesh contained in collector wall because this meshremained unchanged by the CFD mesh process as this component was specified as “fixed withboundary layer.” However, the surface areas associated with the original collectors inlet andoutlets have been completely regenerated and you need to create new components that willbe named inflow and outflow, respectively.

1. Using the Model Browser, rename the collector CFD_tetcore001 to fluid.

This collector will hold all the 3-D volume elements.

2. Click BC s > Organize to move all the elements from the collector CFD_bl001 to collector fluid.

3. Click BC s > Faces to automatically generate the collector f̂aces containing all theexternal faces of the elements in collector fluid.

4. Click BC s > C om ponent > Single to create two new components named inflow andoutflow.



Now you are going to move some of the elements from the collector f̂aces to the collectorsinflow and outflow.

5. In the Model Browser, isolate the ̂ faces component.

6. Click BC s > Organize and click one element on the inlet/inflow plane (the element willbecome highlighted).

7. Click elem s >> by face.

All the elements in the collector f̂aces on the inlet/inflow plane will be selected.

8. Set the dest comp as inflow, and click m ove. Similarly, move the elements from f̂acesassociated with the outlets to the collector outflow.

9. Show the inflow and outflow components in the Model Browser.

When done, you will have all the exterior surfaces colored according to the collectorswhere they have been placed as shown in the following image.

10. The remaining elements in the collector f̂aces are the same as in wall and you candiscard them.

11. Delete both collectors f̂aces and collector CFD_boundary_layer, which is now empty.

Step 7: Export surface and volume mesh and import this mesh intoFLUENT

1. Display only the components containing elements that have to be exported for FLUENT,the components are: fluid, inflow, outflow and wall. All other components should not bevisible.



2. Click the Export Solver Deck icon to open the Export tab.

3. Notice that the File Type is set to CFD. Set the Solver Type to Fluent.

4. In the File field, click on the file icon and specify a name and location for the file.

5. Click Export to export the file.

6. Select Yes to the first message that appears and No to the second message.

Step 8: Create a FLUENT simulation case

If you have access to FLUENT, you can import manifold.cas to create a new FLUENTsimulation case as follows

1. Start FLUENT 3d or 3ddp.

2. From the File menu, select Read, then C ase....

3. Select manifold.cas.

4. Click OK.

After importing this file, you will observe that FLUENT has recognized the boundary zones outflow, inflow and wall by name, and the 3-D volume zone fluid. Zone interior-* isautomatically created by FLUENT containing all the interior faces shared by two 3-D cells.

5. Select Define, then select Boundary C onditions.



6. Select zone inflow, and set the appropriate boundary condition such as mass-flow-inletand velocity inlet.

7. Change the boundary condition type for the remaining surface zones, outflow and wall.

Engineering Solutions allows you to perform the most time consuming tasks of generating thevolume mesh and identifying the boundary zones. Now inside FLUENT the rest of thesimulation tasks can be executed easily.



Appendix: Boundary Layer Mesh with Distributed Thickness Ratio

The boundary layer type mesh generated in this tutorial was generated with uniformthickness. This is OK for a model like this manifold as long as the total boundary layerthickness does not lead to collision or interference that can occur when the sum of the BLthickness is close to or larger than the distance separating boundary layer walls. When suchcollision or interference occurs you have the following options:

Decrease the global boundary layer thickness (throughout / for all the BL surfaces)

Use distributed boundary layer thickness ratios on nodes or collectors/components.This is a capability in HyperMesh that allows you to specify a local value of boundarylayer thickness by specifying the ratio of the local value to the global value. Forexample, if the ratio specified on certain nodes or all the nodes belonging to a collectoris equal to 0.1, then the boundary layer thickness generated around those nodes willbe only 10 percent of the global boundary layer thickness.

The CFD user profile has a tool (Generate BL Thickness) to generate automatically“distributed boundary layer thickness ratios” at each node of the surface mesh so thatboundary layer collision is avoided when using the global or nominal boundary layerthickness. The usage of this tool is explained in Tutorial CFD-1100.

In this appendix you are going to use option B to manually change the BL thickness ratio.

Step A: Prepare data to generate a CFD mesh (boundary layer andcore mesh) using a distributed boundary layer thickness.

1. Create a new component named wall_thinner_bl, and move elements from wall to thisnew collector as shown in the following image.

2. Click BC s > C heck > Edge, then select the collectors wall, wall_thinner_bl, inlet andoutlets.

3. Click find edges. A message indicating that no edges were found will appear on thestatus bar.

4. Click Mesh > Volum e Mesh 3D > C FD tetram esh to access the CFD Tetramesh panel.


6. In the BL parameters subpanel, select the options to specify the boundary layer andtetrahedral core:





BL growth rate= 1.1

7. Select the type of tetrameshing algorithm: Simple Pyramid, Smooth Pyramid, All Prismor All Tetras

8. Ensure the BL only checkbox is not checked.

9. In the Tetramesh parameters subpanel, set the Pyramid transition ratio = 0.8

10. Select the tetrahedral core growth rate switch to Interpolate.


Step B: Define a distributed boundary layer thickness on certaincomponents.

1. In the BL parameters subpanel, ensure that the BL reduction and Pre calc checkboxesare checked and click the green Manual button.

2. The Distributed BL Thickness Ratio dialog opens. This dialog enables you to specifydistributed thickness ratios for groups of nodes or whole components. You can chooseeither Nodes or Components by selecting the associated radio button.

3. Select the C om ponents radio button.

4. Click the yellow Select C om ponents button and select the component wall_thinner_bl.

5. Specify a thickness ratio of value 0.3 and click Assign.

6. Notice that the summary message now indicates the number of BL thickness ratio loads oncomponents:



When the models are more complex it is useful to display surface contours of BL thicknessratio values.

7. Click C ontours of BL Thickness Ratio, and the Contour panel will be automaticallydisplayed.

8. Click contour to inspect the distribution of BL Thickness Ratio on the surface of yourdomain and click return when you are finished. Click C lose to close the dialog.

9. Go to the CFD Tetramesh panel, Boundary selection subpanel. Here all the elements/components that define the surface area on which you need to generate boundary layerswill be selected. This selection is done with the With BL (fixed) selector.

10. Click com ps under With BL (fixed) and select the collectors wall and wall_thinner_bl.

11. Select all the elements/components that define the surface area on which you do notwant to generate boundary layers. This selection is done with the W/o BL (float)selector.

12. Click com ps and select the collectors, inlet and outlets.

13. The switch below the W/o BL (float) selector is set to Remesh. This means that themeshes in the zones defined by collector’s inlet and outlets will be remeshed after beingdeformed by the boundary layer growth from adjacent surface areas.


When this task is finished, note the two collectors automatically created: CFD_boundary_layer and CFD_Tetramesh_core.



15. Inspect the relative size of the boundary layer thickness by masking some of the elementsas shown in the following image. This image shows that the BL thickness on component wall_thinner_bl is only 30 percent of the global BL thickness.

The manual approach followed previously is useful when you need to reduce the BLthickness throughout a component, or at a clearly identified group of nodes.

When you have a very complicated geometry and BL collision is likely to occur, the bestapproach is to use the Generate BL Thickness tool to generate automatically“distributed boundary layer thickness ratios” at each node of the surface mesh. This toolperforms a collision study and assigns a BL thickness ratio to each node of the surfacemesh that requires a reduction of the baseline BL thickness to avoid collision. Usage ofthis tool is explained in Tutorial CFD-1100.

The previous steps illustrate simple and effective steps to reduce the BL thickness on surfacecomponents. This approach is very easy to use and effective when you know how much youwant to increase or decrease the BL thickness all over a component. A similar approach isfollowed to increase/decrease BL thickness on groups of nodes.



CFD-1100: Creating a Hybrid Grid with Varying BoundaryLayer Thickness


Generate boundary layer type meshes with an arbitrary number of layers and thicknessdistribution, which can be used for CFD applications, molding simulations, or otherprocesses.

Generate automatically a distributed thickness distribution to prevent boundary layerinterference /collision in zones where the distance between opposing walls is too smallto accommodate the baseline or nominal boundary layer thickness.

Exercise


1. Click Preferences > User Profiles .


3. Select the radio button C FD and select AcuSolve from the drop down menu.

4. Click OK.

Step 2: Open the model file


2. Select the molding1.hm file from the tutorial directory.

3. Click Open to load this .hm file containing the surface mesh.


The boundary mesh can have any combination of tria/quad elements. You will generateboundary layers on all the surface elements contained in the collector named wall.



Step 3: Check that all the elements in collector wall define a closedvolume

1. Click Mesh > C heck > C om ponents > Edges to open the Edges panel.

2. Click com ps and select the collector wall.

3. Click find edges.


4. Toggle free edges to T-connections.

5. Select the collector wall again and c lick find edges.

The status bar will display, “No T -c onnec ted edges w ere found.

Step 4: Create the CFD mesh

1. Click Mesh > Volum e Mesh 3D > C FD tetra-m esh to open the CFD Tetramesh panel.

2. Select the Boundary se lection subpanel.

You will need to first select all the elements/components that define the surface area onwhich you need to generate boundary layers. This is done by selecting the elements/components under the With BL (float) selector.

3. Under the heading With BL (float), click com ps and select the collector wall.

4. Verify that the switch below the W/o BL (float) selector is set to Remesh. This meansthat the meshes in the zones defined by the collector wall will be remeshed after beingdeformed by the boundary layer growth from adjacent surface areas.


This option is strongly recommended for most cases because it produces boundary layerswith more uniform thickness and better element quality.




7. Select the options to specify the boundary layer and tetrahedral core:



BL growth rate= 1.0 (This non-dimensional factor controls the change in layerthickness from one layer to the next).

8. Under the BL hexa transition mode header, change the selection to All Prisms (Prismto all Layers).

This means that if there are any quad elements in the surface mesh, those will be splitinto two trias each so that there is no need to transition from quad faces to tria faceswhen transitioning from the last boundary layer to the tetrahedral core. This option is veryimportant when there are quad elements on areas with (low) distributed BL thickness ratio, because in such areas the thickness of the transition elements (for example simplepyramid) was not taken into account when doing the interference study to assign dist r ibuted BL thic kness rat io to those elements.


This option generates the boundary layer alone and stops before generating thetetrahedral core. This option modifies adjacent surface meshes to reflect changesintroduced by the boundary layer thickness, and creates a collector named ^CFD_trias_for_tetramesh, that is used to generate the inner core tetrahedral meshusing the Tetramesh parameters subpanel.

10. Check the box for Pre calc and then click the green Auto button.

11. In the Generate Boundary Layer distributed thickness values dialog, notice that thewall component is already selected and has a Bound Type of wall.

This is because the wall component was selected in the Boundary selection subpanel.

12. Specify the Boundary Layer options as shown in the following image.

- The number of layers, first layer thickness and growth rate have been established inthe BL parameters subpanel and are greyed out here. All layers will have the samethickness (except for mesh smoothing operations such as hyperbolic smoothing at



corners).

- Specify a Minimum (Tetrahedral-Core / Boundary-Layer) thickness ratio valueof 2. This means that in areas where there is not enough room to grow the nominal BL (3layers of 2 each), the boundary layers’ thickness will be reduced so that thetetrahedral core thickness is at least 2 times the total boundary layer thickness,except for mesh smoothing operations such as hyperbolic smoothing at corners, andconvex/concave areas.

- The last option, Bound Layer thickness at corners, is a coefficient that controlsthe hyperbolic growth where walls make an angle. The smaller this value is, the thinnerthe total BL thickness in such areas is.

Now you are ready to generate the Distributed BL Thickness loading. Make sure thatnone of the elements specified in the boundary collectors are masked. If they are maskedan error message will indicate that there is a discrepancy between the total number ofelements in the components and the tria3/quad4 elements found. If you have maskedelements, you can access the Mask (F5), and press unm ask a ll.

13. Click G enerate D istributed BL Thickness Ratio.

14. If the model already contains boundary layer thickness ratios, then a pop-up message boxwill ask you if you want to keep such loading or if you want to delete them. Most of thetime you will want to clear the existing boundary layer thickness ratios; press Yes. Insome special cases you may want to keep them, if more than one loading value isspecified at a node, the minimum value is used when generating the mesh.

After a few seconds you will see a pop-up message indicating the number of distributedboundary layer thickness values included in collector ^CFD_BL_Thickness.



15. Click C lose in the Generate Boundary Layer distributed thickness values window.



For a detailed explanation of each option, please refer to the online help.

18. Set the tetrahedral core growth rate to Interpolate.



When this task is finished, two collectors are automatically created: CFD_bl001 andCFD_tetcore001.


Step 5: Mask elements to inspect the boundary layers’ thickness onthinner areas

1. Access the Mask panel by using the shortcut key F5.

2. Select elements to be masked.

3. Click m ask.

The following images illustrate how BL interference has been avoided by reducing the BLthickness.



Step 6: Generate a pure tetrahedral mesh for moldflow

The mesh needs to consist of tetrahedral elements only. This was accomplished by generatingtetras directly in the boundary layer. However, if you need to split penta / wedge elementsinto tetras, use the procedure below.

1. Click Mesh > Edit > Elem ents > Split Elem ents.

2. Select the solid e lem ents subpanel.

3. Set the switch to split into tetras.

4. Select elem s >> by collector and select wall.

5. Click split.

Now you have a mesh consisting of tetrahedral elements only.

The objective of this tutorial is to illustrate how you can generate very thin boundary layerswithout interference. However, such thin boundary layers can lead to element with a highaspect ratio if the size of the surface mesh is not small enough. If you need to limit thetetrahedral elements’ aspect ratio (for example, < 5), then you need to use a fine enoughmesh on the wall component so that thin boundary layers do not produce high aspect ratioelements. For example, in this case, the minimum value of tetra collapse of all tetrahedral coreelements was 0.2, but after you split the BL penta / wedge elements into tetras, the minimumvalue of tetra collapse of all tetrahedral elements becomes 0.04. This occurs because the BLpenta elements are thin compared to their triangular face area size.

Summary



HyperMesh allowed you to generate high-quality boundary layer meshes on parts with verythin walls. To accomplish this you first need to use the utility Generate Distributed BLThickness Ratio to generate load collector ^CFD_BL_Thickness. This load collector is thenused when you enable distributed thickness. As shown in the cross-sectional images, themesh is very smooth and is of excellent quality.



CFD-1200: CFD Meshing with Automatic BL ThicknessReduction

Mesh generation in domains bounded by surfaces that are very close to one another insome areas.


Generate meshes for most CFD codes (for example Acusolve, CFD++, CFX, Fluent,StarCD, SC/Tetra) using the CFD Tetramesh panel.

Generate boundary layer type meshes with arbitrary number of layers and thicknessdistribution in domains defined by surfaces that are very close to one another in someareas. More specifically, in some areas the clearance or separation of boundingsurfaces is not enough to accommodate the user specified nominal boundary layerthickness.

Generate a distributed thickness “loading” that prevents boundary layer interference /collision in zones where the distance between opposing walls is too small toaccommodate the baseline or nominal boundary layer thickness.

Exercise

Step 1: Open the exercise file


2. Select the manifold_inner_cylinder.hm file from the directory

<install_directory>\tutorials\es\cfd.

3. Click Open to load this file containing the surface mesh.


You would like to generate boundary layers on all the surface elements contained incomponents wall and wall_cyl. However, there is an area close to the end of wall_cyl



where the clearance between wall and wall_cyl is very small. This can be easily observedin this case by changing the visibility of component wall, as shown in the following image.

In more complex models it is not possible to visually identify all the zones where there isnot enough space to growth the “baseline” or nominal boundary layer as specified in termsof the number of layers, first layer thickness and growth rate. This is not a problembecause the automatic distributed thickness “loading” computation takes into account allpossible interference cases. This is demonstrated in this tutorial.

5. Select Preferences> User Profiles to set the User Profile.

6. Select Engineering Solutions as the Application.

7. Select the C FD radio button and then select AcuSolve from the drop down menu.

Step 2: Check that the surface elements define a closed volume

1. Click Mesh > C heck > C om ponents > Edges.

2. Click com ps and select all collectors that define the domain’s surface, namely inlet,outlets, wall and wall_cyl.



4. Toggle the free edges switch to T-connections.

5. Select the components again and click find edges.

The status bar will display, “No T -c onnec ted edges w ere found.

Step 3: Generate a BL distributed thickness loading to preventboundary layer interference

1. Click Mesh > Volum e Mesh 3D > C FD tetram esh.

2. Click the Boundary se lection subpanel.



3. Under the heading With BL (fixed), click com ps and select the collectors wall andwall_cyl.


5. Ensure that the switch below the W/o BL (float) selector is set to Remesh. This meansthat the surface meshes associated with those components will be remeshed or rebuiltafter shrinking due to boundary layer growth from adjacent boundary layer components.


7. Click the BL param eters subpanel.

8. Set the following fields:



BL growth rate = 1.2 (This non-dimensional factor controls the change in layerthickness from one layer to the next).

BL hexa transition mode = All Prisms (Prism to all Layers). This means that ifthere are any quad elements in the surface mesh, those will be split into two triaseach so that there is no need to transition from quad faces to tria faces whentransitioning from the last boundary layer to the tetrahedral core. This option is veryim portant when there are quad elements on areas with (low) distributed BL thicknessratio, because in such areas the thickness of the transition elements (for example,simple pyramid) was not taken into account when doing the interference study toassign distributed BL thickness ratio to those elements.

9. Check the boxes for BL reduction and Pre calc and then click the green Auto button.The Generate Boundary Layer distributed thickness values dialog opens.

Notice that the four components selected in the Boundary selection subpanel arealready added.

10. Set the correct Bound Type for each one of the selected components. You want togenerate a boundary layer from components wall and wall_cyl, therefore, you will leavewall as their Bound Type. Also verify that the Bound Type of components inlet andoutlets is set to in/outlet as shown, following:



Note:

A component with Bound Type: wall indicates that you are going to generate a boundarylayer mesh on the component later on when you generate the mesh. Therefore, the samecomponent should be consistently specified with the comps selector for the With BL(fixed or float) in the Boundary selection subpanel.

A component with a Bound Type: slip, symmetry, in/outlet, or farfield indicates thatyou are NOT going to generate a boundary layer mesh on the component. Therefore,when you generate the mesh this component should be consistently specified with thecomps selector for the W/o BL (fixed or float) in the Boundary selection subpanel.

11. Specify the Boundary Layer options as shown in the following image.

The first three fields are set in the BL parameters subpanel and cannot be changedhere. All layers will have the same thickness except in area affected by the distributedthickness "loading" and also mesh smoothing operations such as hyperbolic smoothingat corners.

Specify a Minimum (Tetrahedral-Core / Boundary-Layer) thickness ratio valueof 2.0. This means that in areas where there is not enough room to grow the nominalBL (5 layers starting with a thickness of 0.5 and increasing with a grow rate of 1.2),the boundary layers’ thickness will be reduced so that the tetrahedral core thickness isapproximately at least 2.0 times the total boundary layer thickness, except for meshsmoothing operations such as hyperbolic smoothing at corners and convex/concaveareas.

The last option, Bound Layer thickness at corners, is a coefficient that controlsthe hyperbolic growth where walls make an angle. The smaller this value is, the thinnerthe total BL thickness is in such areas; values less than 1 produce thinner layers andvalues greater than 1 produce thicker layers.

Now you are ready to generate the Distributed BL Thickness loading. Make sure that



none of the elements specified in the boundary collectors are masked. If they are maskedan error message will indicate that there is a discrepancy between the total number ofelements in the components that you specified and the number of tria3/quad4 elementsfound (displayed). If you have masked elements, you can use m ask (F5), and pressunm ask a ll.

12. Click G enerate D istributed BL Thickness Ratio.

If the model already contains boundary layer thickness ratios, then a pop-up message boxwill ask you if you want to keep such loads or if you want to clear/discard them. Most ofthe time you will want to clear the existing boundary layer thickness ratios; press Yes. Insome special cases you may want to keep them, if more than one loading value isspecified for a node, the minimum value is used when generating the mesh.

13. After a few seconds you will see a pop-up message indicating the number of distributedboundary layer thickness values included in collector ^CFD_BL_Thickness.

14. Click C lose in the Generate Boundary Layer distributed thickness values dialog.

Step 4: Generate the boundary layer and tetrahedral core mesh

1. In the CFD Tetramesh panel, click the Tetram esh param eters subpanel.

2. Set the switch for the tetrahedral mesh generation algorithm to Optimize Mesh Quality.

3. Ensure the tetrahedral grow rate is switched to Interpolate.

4. Click m esh to generate the mesh. If collectors CFD_bl001 and CFD_tetcore001 arepresent, you will be asked if you want to delete the elements in those collectors. Almostalways you select Yes.

When this task is finished two collectors are created: CFD_bl001 and CFD_tetcore001.



Step 5: Mask elements to inspect the boundary layers’ thickness onthinner areas

1. Select the XZ Left Plane View icon .

2. Access the Mask panel by using the shortcut key F5.

3. Select elements to be masked by pressing SHIFT and the left mouse button, then movethe cursor so that the rubber band covers the upper half of the model.

4. Click m ask.

5. Click the XY Top Plane View icon .

6. Zoom in into the area where the bounding surfaces come close together. The followingimage illustrates how BL interference has been avoided by reducing the BL thickness.

7. Click return to close the Mask panel.

Step 6: Arrange volume and surface components before exporting themesh for CFD solvers

First you need to put in the same component all the elements that represent a single fluid



and/or solid domain. In this case you have a single fluid domain, therefore you proceed asfollows:

1. Rename the CFD_Tetramesh_core component. Typically, select a name “fluid*,” for

example, fluid. In the Model Browser, select C FD_tetcore001, right-click, select

Renam e, and then type the new name, fluid.

2. Click BC s > Organize.

3. Click elem s >> by collector and select the collector C FD_bl001.

4. In the dest component field, select fluid.

5. Click m ove and then click return.

Now you have all the volume elements in component fluid. The surface mesh of thiscomponent is typically different from the surface mesh that was used to define theboundary of the domain. For this reason, and to have consistent surface zones to imposeboundary conditions in most CFD solvers, you are going to create new boundarycomponents that will be used when exporting the mesh for the CFD solver of your choice.To accomplish this you first extract the surface mesh of component fluid. You do this bygenerating the surface elements.

6. Click BC s > Faces.

7. Select the component fluid, and click find faces. All boundary faces are placed in thecomponent f̂aces.

8. Create new, empty components to place the elements from ^faces so that when thesecomponents are later exported, they can be used to set a boundary condition in your CFDsolver. In the Model Browser, right-click on C om ponent, and then select C reate.

9. Enter the Name as wall_exterior. Leave Card image as none, and c lick C reate.

10. Create three more empty components with the names wall_cylinder, inlet_annulus andoutlets3.



11. Move the elements from component f̂aces into the newly created components. This isdone for clarity; however, most of the time you create one fewer component and yourename ^faces which retains the remaining elements after you move elements to thenewly created surface components. Organize the components by using the Organizepanel. Select BC s > Organize.

12. Set dest component to wall_exterior, then pick one element on the exterior wallsurface in the f̂aces component.

13. Click the elem s switch and select by face.

This will recursively select all the elements attached to the picked element as long as theadjacent elements are within a break angle less or equal to the value specified in thefeature angle field (Preferences > G eom etry Options > Mesh subpanel).

The surface mesh in f̂aces is such that the zones that you want to organize/move makean angle close to 90 degrees and their boundaries, therefore this is a very easy job to dowith a default feature angle of 20 or 30 degrees.



14. Having selected all the elements that should go to component wall_exterior, click m ove.

15. Now set the dest component to outlets3 and pick at least one element on each one ofthe three separate outlets as shown in the following image.

16. Click the elem s switch and select by face.

17. Having the elements on the three outlets selected, press m ove and those elements aremoved to component outlets3.

18. Set dest component to inlet_annulus and pick one element as shown in the following

image.

19. Right-click the elem s switch and select by face.

20. Having all the elements on the inlet annulus selected, press m ove and those elements aremoved to component inlet_annulus.

Now that all the remaining elements in component f̂aces are the elements that you wantto move to component wall_cylinder.

21. Set dest component to wall_cy linder.

22. Click on elem s and in the panel area and select by collector.

23. Select the component ^faces.

24. Click m ove and then click return.



The elements are moved to component wall_cylinder as shown in the following image.

As mentioned previously, more often than not it is easier to rename/recolor component f̂aces.

Step 7: Exporting the mesh

1. Verify that only the components that you want to export are displayed. All othercomponents should NOT be displayed, as illustrated in the following image of the ModelBrowser.

2. Click the Export Solver Deck icon to open the Export tab. Select the CFD file formatof your choice (such as Acusolve, CFD++, CFX, CGNS, Fluent, or StarCD) to export thegrid or mesh.

Note: solvers like Acusolve and FLUENT have certain requirements when the domaincontains different fluids and/or solids. This is described in other sections of theEngineering Solutions Help system.

Summary

Engineering Solutions allowed you to generate high-quality boundary layer meshes on partswhere the clearance or separation of the bounding surfaces is not enough to accommodatethe user specified nominal boundary layer thickness. To accomplish this you first used the CFDutility Generate Distributed BL Thickness Ratio to generate load collector^CFD_BL_Thickness. This load collector is then used when you enable distributedthickness. As shown in the cross-sectional images, the mesh is very smooth, free ofcollisions, and is of excellent quality.



CFD-1300: Plane 2-D Meshing with Boundary Layers

2-D Boundary Layer Mesh generation in domains bounded by edges


Generate 2-D boundary layer type meshes with an arbitrary number of layers andthickness distribution in domains defined by edges.

Generate 2-D boundary layer type meshes in areas where the clearance or separationof bounding edges is not enough to accommodate the user specified nominal boundarylayer thickness / number or layers.

Exercise


1. Click File > Open.

2. Navigate to the directory <installation_directory>\tutorials\es\cfd and select

the manifold_inner_cylinder_2d.hm file.

3. Click Open to load the file containing the edges.

4. Inspect the edges elements that will be used to generate the volume mesh.

The boundary mesh should only consist of PLOTEL (elem type) elements. You want togenerate boundary layers on all the edges contained in the collectors called wall andinner wall.

5. Select Preferences > User Profiles to set the User Profile.



6. Select Engineering Solutions as the Application.


Step 2: Check that all the elements in collectors wall, inner wall, inlet,and outlets define a closed loop. (This step is for information only; it isoptional for this tutorial)

Usually, this step is not necessary because the collectors containing edge elements (PLOTEL)are extracted from 2-D surface meshes that naturally have free edges forming “closed” loops.However, there is a possibility that there may be duplicate nodes, and for this reason it isadvisable to perform the following test:

1. Click BC s > C heck > Edge.

2. Click com ps.

3. Select the collectors wall, inner_wall, Inlet and Outlet.

4. Click se lect.

5. You need to ensure that the tolerance value is smaller than the minimum element length.To do this, first find the minimum element length.

Click Mesh > C heck > Elem ents > C heck Elem ents.

6. Select the radio button 1-d.

7. Click the top length button.

A message indicates the minimum element length is 3.09, therefore you can safely use atolerance of 3.

8. Click return to close out of the current panel.

9. In the Edge panel, enter 3.0 in the tolerance = field and then click Prev iew Equiv. A

message indicating that 0 nodes w ere found will appear on the status bar.

Step 3: Generate a 2-D BL Mesh

1. Click Mesh > Surface Mesh 2D > 2D Mesh with BL.

2. Click the 2D Native BL (planar) tab.



3. Set the default values to be assigned when adding collectors:

1st Layer Thickness = 0.5

Growth Rate = 1.1 (This non-dimensional factor controls the change in layer

thickness from one layer to the next)

Bound Type = Wall (Will generate a boundary layer mesh)

Number of boundary layers = 6 (value must be >= 0, as a zero value leads to no

boundary layers even when Wall type is specified)

4. Uncheck the Retain node seeding on edge w/o BL option.

5. Click Add collector.

6. In the selector panel, click com ps.

7. Select all four components.

8. Click se lect.

9. Click proceed.

10. In the 2D Boundary Layer Mesh window, all the selected components will be displayed inthe Component list as shown below:



11. Default values of boundary layer mesh (1st Layer Thickness, Growth Rate, and BoundType) will be assigned to each component. To remove one or more components from thegroup, select those components from the list and click Rem ove.

12. In the 2D Boundary Layer Mesh window, set the Bound Type value for componentsInlet and Outlet as In/Outlet.

The objective is to not generate boundary layers along the Inlet and Outlet components.

Note: those elements may be remeshed based on the adjacent elements’ size.

13. Click G enerate 2D BL Mesh to generate the mesh.

When this task is finished, two collectors are automatically created: 2DBLMesh and2DCoreMesh, as shown in the following image. Note that the quality of the mesh may notbe very good, as described, following. In the next steps you will change some defaultparameters to allow boundary node insertion and movement.

As indicated previously, components with Bound type In/Outlet will be remeshed basedon the adjacent elements’ size. The two following figures illustrate the case where aninlet/outlet is defined with a single large element, after meshing the element size in thisarea has been reduced to obtain a smooth element size transition, leading to an excellent



mesh quality.

Step 4: Changing Mesh Quality

Often it may happen that boundary layer elements will have bad quality due to high aspectratio. Such elements are created because of the large boundary edge length as shown in thefollowing image.



This problem can be resolved by limiting the maximum perimeter elements’ aspect ratio. Themaximum boundary elements’ aspect ratio can be achieved using two approaches:

By addition of new nodes on the boundary / perimeter.

By node movement on the boundary / perimeter.

1. Activate the Allow boundary node insertion checkbox.

- Refine the boundary edges by insertion of nodes on boundary edges. New nodeinsertion is controlled by the specified maximum perimeter element aspect ratio.

Or

- Activate the Allow boundary node movement checkbox.

This option is used to move boundary nodes along the original boundary. Boundary nodemovement is controlled by the specified maximum perimeter element aspect ratio.

Enter the maximum perimeter element aspect ratio as shown in the following image:


If the model already contains collectors 2DBLMesh and 2DCoreMesh, then a pop-upmessage will ask you if you want to delete components 2DBLMesh and 2DCoreMesh



before mesh creation or if you want to add newly created elements to the samecollectors. Most of the time you will want to clear the existing mesh: click Yes. In somespecial cases you may want to keep them.

When this task is finished, two collectors 2DBLMesh and 2DCoreMesh are updated withnew elements as shown in the following image:

3. You can check the element’s aspect ratio by using the shortcut key F10 and selectingthe 2-d page.



When the perimeter has sharp angles as shown in the following image, triangular elementsare added to the boundary mesh to achieve a smoother transition of element sizes, andmesh smoothing also contributes to increase the mesh quality.

Also note that the automatic mesh generator performs a collision detection and avoids



boundary layer interference by reducing the boundary layer thickness, as shown in thefollowing inset:

Step 5: Use a distributed boundary layer thickness to generate aboundary layer and core

The boundary layer type mesh generated in this tutorial was generated with uniformthickness. This is OK for a model like this manifold as long as the total boundary layerthickness does not lead to collision or interference that can occur when the sum of the BLthickness is close to or larger than the distance separating opposite walls. When such collisionor interference occurs you have the following options:

Decrease the global boundary layer thickness (throughout / for all the BL edges).

Decrease locally the boundary layer thickness (BL edges around critical zones only).

Decrease locally the boundary layer thickness.

1. In the 2D Boundary Layer Mesh window, click Reject to remove the created mesh.

Collectors 2DBLMesh and 2DCoreMesh will be deleted.

2. Click C lose to close the pop-up window.

Create new components (empty) to place the PLOTEL elements at critical zone (areawhere boundary layer elements may lead to collision).

3. Open the Model Browser.

4. Click BC s > C om ponents > Single.



5. Enter name as wall_critical.

6. Click C reate and then C lose .


8. Select the boundary edges (PLOTEL) around the area where boundary layer elements maylead to collision. Refer to the following image for element selection.

9. Set the dest group/dest component switch to dest com ponent = and select thedestination collector as wall_critica l.

10. Click m ove to move the selected PLOTEL elements to the destination collector.

11. Click Mesh > Surface Mesh 2D > 2D Mesh with BL.

12. In the 2D Native BL (planar) tab, click Add collector.

13. In the panel area, click com ps.

14. Select the component wall_critical.

15. Click se lect.

16. Click proceed.

The component wall_critical has been added to the component list.

17. Set 1st Layer Thickness of component wall_critical to 0.4.




When this task is finished, two collectors are automatically created: 2DBLMesh and2DCoreMesh.

19. Now you can zoom in around component wall_critical and notice how boundary layerinterference has been avoided by reducing the total boundary layer thickness as shown inthe following image:

Summary

In this tutorial you generated 2-D meshes with boundary layers on a complex cross section.You obtained a high quality mesh by allowing boundary node insertion and movement.Engineering Solutions automatically cuts back the number of layers when boundary layer



collision occurs, thus producing a consistent mesh even in narrow areas. In narrow passagesyou can also reduce the total boundary layer thickness by starting with a smaller first layerthickness and/or a smaller growth rate.



CFD-1400: Wind Tunnel Mesh

In this tutorial you will generate a wind tunnel type mesh for external CFD analysis. The meshconsists of a Cartesian hexa-mesh for the far field, and a hybrid grid (tetras with boundarylayers) in the vicinity of the object.

The tutorial includes the following steps:

Setting the user profile

Opening the model file to be used

Using the wind tunnel functionality

Surface meshing

Volume meshing using the CFD Tetramesh panel

Organizing the model and preparation for CFD export

Export for Fluent

Exercise


1. From the menu bar, select Preferences, then User Profiles.

2. For Application, select Engineering Solutions, click the C FD radio button and selectAcuSolve from the drop down menu.

3. Click OK.


1. From the toolbar, click the Open Model icon .

2. Select the airplane.hm file from the directory <install_directory>\tutorials\es\cfd

.

3. Click Open to load the file.



Step 3: Use the Wind Tunnel Mesh tool

1. Click Mesh > Volum e Mesh 3D > W ind Tunnel.

The Wind-Tunnel tab opens, displaying instructions for using this tool.

2. Enter values for your model as shown in the following image:

3. Click G enerate.

A pop-up message will display the estimated number of hexahedral elements that will becreated with the specified minimum hex cell size.

4. Click Yes on the pop-up message.

The Wind Tunnel Mesh tool generates hexa, pyramids and shell elements and groupsthem into several collectors.



You may need to rotate the model to obtain this view.

Step 4: Generate a shell mesh on the airplane

1. In the Model Browser, expand Component, right-click plane, and select Isolate.

2. Click Mesh > Surface Mesh 2D > Autom esh.

This automatically loads the surface deviation subpanel.

3. With surfs selected in the toggle, hold SHIFT and drag a box around the entire visibleairplane geometry.

You may need to resize the display first.

4. For element size =, enter 10.

5. For growth rate =, enter 1.2.

6. For min elem size =, enter 2.

7. For max deviation =, enter 0.1.

8. For max feature angle =, enter 15.

9. Set mesh type: to trias.

10. Ensure toggles are set to elems to surf comp and first order.

11. Click m esh.



A message on the status bar indicates the number of elements created.

Step 5: Mesh the box sym component with an element size of 20

1. In the Model Browser, show the elements and geometry for box_sym.

2. In the Automesh panel, click the size and bias subpanel.

3. With the surfs toggle active, click any visible part of the box to select it.

4. For element size =, enter 20 and set the mesh type to trias.

5. For map:, activate the checkboxes for size and skew.

6. Click m esh.

The component is meshed. A message on the status bar indicates the number of elementscreated.

7. Click return twice to return to the main menu.



Step 6: Equivalence nodes in box_sym

1. In the Model Browser, right-click on the component sym p and select Show.


3. Click the yellow com ps button and select the components box_sym and sym p.

4. For tolerance =, enter 0.1.

5. Click prev iew equiv.

A message in the status bar indicates the number of nodes found.

6. Click equiva lence.

The nodes are equivalenced.


Step 7: Create new component box_ground


2. In the Name: field, enter box_ground.

3. Click C olor and select magenta.

4. Click C reate.

The new collector has now been created.



5. Close the dialog.

Step 8: Generate a surface and a tria mesh on the bottom of the box

1. In the Model Browser, turn off the element display for symp and turn on the display forground.

2. Click Mesh > Surface Mesh 2D > Surface/Mesh > Spline.

3. Set the selector toggle to nodes.

4. Click the nodes selector to open the extended entity selection menu and pick by path.

5. Set the second toggle to surface only.

6. Pick the nodes by path on the perimeter of the box bottom, as in the following image:

7. Click create.

8. Click return.


10. Select the size and bias subpanel, ensure the selector is set to surfs and the elementsize field is set to 20.

11. In the graphics area, click the box_ground surface.

12. Click m esh.

A message on the status bar will indicate the number of elements created.

13. Click return twice to return to the main menu.

Step 9: Equivalence nodes to achieve a closed volume




2. Click the yellow com ps button and select the components plane, box_sym, ground,trias_hexas_pyras, and box_ground.

3. Set the tolerance field to 0.1.

4. Click prev iew equiv.

5. Click equiva lence.

6. Click return.

7. In the Model Browser, turn off the display of ground, and turn on the element displayof trias_hexas_pyras.

8. Return to the Edges panel.

9. Hold SHIFT and drag a box around all the visible components to select them all.


A message on the status bar indicates that no edges were found.

11. Select the components again and click prev iew equiv.

A message on the status bar indicates that 0 nodes were found. This ensures that thevolume is enclosed, which is necessary for the following tetra meshing step.

12. Click return.

Step 10: Mesh the closed volume


2. Under the With BL (fixed) header, click the com ps selector and select the componentplane.



3. Under the W/o BL (fixed) header, click the com ps selector and select the componentsbox_sym, box_ground and trias_hexas_pyras.

4. Click the BL param eters subpanel.

5. For Number of Layers = enter 3.

6. For First layer thickness = enter 0.7.

7. On the Tetramesh parameters subpanel, set the toggle to Interpolate.

8. Click m esh.

The mesh may take a few minutes. When the mesh is complete, a message in the statusbar will indicate the number of nodes and elements created.

Note that two new components, CFD_tetcore001 and CFD_bl001, appear in the ModelBrowser.

9. Click return.

Step 11: Inspect the mesh

1. Click Mesh > C heck > H idden Lines. In the panel, deactivate the clip boundaryelements checkbox.

2. Click show plot and then check and then uncheck the xy plane, yz plane and xz planecheckboxes to display the model in different views.



3. Rotate and inspect the mesh from the side of the model.

4. Click and hold one of the corners of the model. While keeping the mouse button down,drag the corner of the model forth and back to sweep the cutting plane.

5. Click return.

Step 12: Organize faces

1. In the Model Browser, turn off the display for plane, box_sym, trias_hexas_pyrasand box_ground so that only CFD_tetcore001 and CFD_bl001 are visible.


3. Hold SHIFT and drag a box around the visible components to select them.

4. Click find faces.

Note that a new component named f̂aces appears in the Model Browser.

5. Click return.



6. In the Model Browser, turn off the display of the elements of CFD_tetramesh_core andCFD_boundary_layer.

7. Click BC s > Organize .

8. Click elem s and select on plane.

9. Pick three nodes on the f̂aces component, on the face that intersects the airplanemodel.

A good way to determine which area to select is to isolate the display of the box_symgeometry. This will show you the face to focus on. Turn the display of the f̂acescomponent back on, and select your three nodes.

10. Click se lect entities.

11. Click dest com ponent = and select sym p.

12. Click m ove.

13. Click elem s >> on plane.

14. Pick three nodes on the bottom of the f̂aces component.

A good way to determine which area to select is to isolate the display of the box_groundgeometry. This will show you the face to focus on. Turn the display of the f̂acescomponent back on, and select your three nodes.



15. Click se lect entities.

16. Click dest com ponent = and select ground.

17. Click m ove.


Step 13: Delete collectors

1. In the Model Browser, right-click the component ^faces, and select Delete.

2. In the pop-up dialog, click Yes to confirm the deletion.

3. In the Model Browser, turn on the display of CFD_tetcore001 and CFD_bl001.

4. Press the CTRL key and select edges_xz and edges_xy in the Model Browser.

5. Right-click and select Delete.

6. In the pop-up dialog, click Yes to confirm the deletion.

7. In the same way, also delete trias_hexas_pyras, box_sym and box_ground.

Step 14: Organize components




2. Click elem s and select by collector.

3. Select C FD_tetcore001 and C FD_bl001.

4. Click se lect.

5. Click dest com ponent = and select fluid_hex.

6. Click m ove.

When the move is complete, nothing should be visible in the graphic area.

7. Click return.

Step 15: Use the Model Browser to rename and delete components

1. In the Model Browser, display elements for fluid_hex.

2. Right-click fluid_hex in the Model Browser and select Renam e.

3. Enter the new name as fluid.

4. Select C FD_tetcore001 and C FD_bl001 and delete them using the process described inStep 14.

5. Right-click C om ponent and select Show to show all remaining components in the graphicarea.

Step 16: Export the file as .cas

1. Click Export Solver Deck .



2. Ensure that CFD is selected for the File Type, and pick Fluent for the Solver Type.

3. Use the File field to navigate to the destination folder and enter the namewind_tunnel_mesh.

4. Click Export.

A pop-up dialog appears. After reading the dialog, click Yes.



5. In the pop-up dialog that appears, you are asked whether to reuse the setup from anexisting Fluent file. Since you just generated the grid and do not have a set up file (*.cas

), click No.

It may take a few minutes for the file to be created.



6. When the file creation is complete, a pop-up window appears. Click OK.



CFD-1500: Hexcore Meshing with Boundary Layer

In this tutorial you will learn how to generate a hexcore mesh with a boundary layer. Includedare the following steps:

Tria surface meshing

Boundary layer generation

Generation of the hexcore mesh, pyramid elements and the tetra mesh

Preparation of the model for the export

Exercise


1. From the menu bar, select Preferences, then User Profiles.

2. For Application, select Engineering Solutions, click the C FD radio button and thenselect AcuSolve from the drop down menu.

3. Click OK.



2. Select the ujoint_cfd.hm file from the directory

<install_directory>\tutorials\es\cfd.




Step 3: Generate a mesh on the surface

1. In the Model Browser, expand Component, right-click on it and select Show.


3. Click the size and bias subpanel.

4. Set the element size = field to 5.0.

5. Set the mesh type to trias.

6. Ensure that both the size and skew checkboxes are activated.


8. Click the yellow surfs button and selected all.

9. Click m esh.


10. Click return twice to close the panels.



Step 4: Mesh the hex-core

1. Click Mesh > Volum e Mesh 3D > Hex-core.

2. Enter the parameters as shown in the image below:



3. Checking the box for Generate exterior tetrahedral mesh and Boundary Layer makesthe bottom part of the tab editable. Enter the Number of layers as 3, the First layer

thickness as 0.4 and the Growth rate as 1.2.



4. Under the header With boundary layer, click the C om ponents button and select thecomponent wall.

5. Under the header W/o boundary layer, click the C om ponents button and select inflowand outflow.

6. Click G enerate just above the Report area. If a message appears, select Yes. After themeshing finishes, a message appears stating that additional components have beencreated.

7. Check the Model Browser to see all the new components created.

8. Press F5 to open the Mask panel. While holding the shift key down, draw a box aroundroughly half of the model, and click m ask. This will display the inside of the model.




Step 5: Prepare the model for export

1. In the Model Browser, right-click on C om ponent and select C reate.

2. Enter the name as fluid and click C reate.

3. Right-click on C om ponent again select Show to remove the masking effect.

4. From the View menu, select Browsers > HyperMesh > Mask.

5. Display only the volume elements by clicking on the "1" in the row for 3D elements, asshown below:



6. Click Mesh > Organize.



7. Click elem s and select displayed.

8. Click dest com ponent = and select the fluid component.

9. Click m ove, and then click return.

10. In the Mask Browser, set only the 2D elements to display.

11. Click Mesh > Delete > Elem ents. Click the yellow elem s button and select displayed.

12. Click delete entity. This deletes all 2D elements from the model.

13. While still in the Delete panel, click the toggle and switch from elem s to com ps. Clickcom ps and select the components that are now unused:

CFD_boundary_layer

hexcore

pyramids

faces_pyra_hex

tetras_exterior

14. Click delete entity and click return.

15. In the Model Browser, right-click on C om ponent and select Show to display theremaining components. Only volume elements are now available in the model.


17. Click the com ps button and select the fluid component.

18. Enter the tolerance as 0.010 and select find faces. Click return to close the panel.




20. Click elem s and select the elements on the inlet.

21. Click dest com ponent = and select the inflow component. Click m ove.

22. Click elem s again and select the elements on the outlet.

23. Click dest com ponent = and select the outflow component. Click m ove.

24. Click elem s again, select by collector and select ^faces.

25. In the dest com ponent = field, select wall and click m ove. This will move the remainingelements in the f̂aces component into the wall component.

26. In the Model Browser, delete the f̂aces component.

27. Display all the components and export the model to the CFD solver of your choice.



CFD-1600: Using Distributed Thickness for VaryingBoundary Layer Thickness

In this tutorial you will learn how to

Generate a structured quad surface mesh

Adjust the boundary layer thickness manually

Generate a hybrid grid (tetramesh with boundary layer)

Export the model for a CFD solver of your choice

Exercise


1. From the menu bar, select Preferences > User Profiles.



4. Click OK.



2. Select the wing.hm file from the directory <install_directory>\tutorials\es\cfd.




4. In the Model Browser, click on C om ponent and expand the folder, then right-click onbox and select Hide.

5. Right-click on plane and select Show.

Step 3: Generate a mesh on the surface


2. Click the size and bias subpanel.

3. Set the element size = field to 5.0.

4. Set the mesh type to quads only.

5. Ensure that both the size and skew checkboxes are activated.


7. Click the yellow surfs button. In the graphics area, use the Shift key and the left mousebutton to draw a box around the wing to select the entire image.

8. Click m esh.




Step 4: Adjust the node seeding on each edge to get a structured quadmesh

1. While in the density subpanel, change the elem density = field to 17.

2. Click the edge button just above the elem density field and graphically select both left-hand edges of the wing.

The entire edge is selected.

3. Rotate the model and repeat Step 2 for the other end.

To get a structured quad mesh adjust the number of nodes on the edges in such a way so that twoopposite edges have the same number of nodes. See the image below:



4. Click the edge button next to adjust: and select the edge as shown in the image below:

5. Now adjust the node seeding on the two remaining edges (leading edge and training edge)to 47 to get a uniform quad mesh.

6. Click m esh.




Step 5: Define the region for a thinner BL thickness


2. Enter the name of the new component as BL_thin and click C reate and then C lose.


4. With the elems button highlighted, use the Shift key and the left mouse button to draw abox around a portion of the elements on the wing (see the image below).

5. Click the dest com ponent button and select the component BL_thin.




Step 6: Mesh the surface of the box

1. In the Model Browser, turn on the display of the box component, and then click F on thekeyboard to fit the model into the graphics region.

2. Click Mesh > Surface Mesh 2D > Autom esh and then select the s ize and biassubpanel.

3. With the surfs button highlighted, select the six surfaces of the box.

4. Set the element size field to 30, and change the mesh type toggle to trias.

5. Click m esh.


Step 7: Volume meshing


2. Click on the Boundary se lection subpanel. Under the heading With BL (fixed), click thecom ps button and select the plane and BL_thin components.

3. Under the heading W/o BL (float), click the com ps button and select the boxcomponents.

4. Click on the BL param eters subpanel.

5. In the Number of Layers field, enter 4.

6. In the First layer thickness field, enter 0.3

7. Check the boxes for BL reduction and Pre calc and then click the green Manual buttonto open the Distributed BL Thickness Ratio dialog.

Note: In the dialog, you can select nodes or components, and define a scaling factor forthe boundary layer thickness at this location. For example, a scaling factor of 0.5will reduce the BL thickness in this region to one half of the original BL thickness.

8. In the dialog, click the C om ponents radio button.



9. Click Select C om ponents and select the component BL_thin.

10. Click proceed.

11. In the Thickness Ratio field, enter 0.1.

12. Click Assign, and then click C lose.

Note: For all of the nodes in the selected component BL_thin, the boundary layerthickness will be reduced to 1/10 of its initial size. A smooth thickness transitionwill be used.

The defined scaling factor is now stored in the load collector ^CFD_BL_Thickness, asshown in the Model Browser.

13. In the Model Browser, right-click on the box component and select Hide. Right-click onthe load collector ^C FD_BL_Thickness and select Show. Check the value of the scalingfactor to make sure it is correct and if it is attached to the correct component.



14. Click on the Tetram esh param eters subpanel. Select Interpolate for the tetrameshinggrowth algorithm behavior.

15. Click m esh. Two new components are generated containing the boundary layer elementsand tetra elements.

16. To check the result, mask parts of the mesh and compare the thickness of the boundarylayer for the plane component with the thickness of the BL_thin component. You can dothis in the Distance panel. You will see that the thickness ratio is 1/10, as expected.



Due to smoothing algorithms for the boundary layer, the thickness ratios can differ fromthe user-defined values, for some use cases.

Step 8: Prepare the model for export

1. In the Model Browser, right-click on C om ponents and click Show to display allcomponents.

2. Click BC s > C om ponents > Single. Enter the new name as fluid.

3. Repeat Step 2 to create more collectors, with the names inflow, outflow, wall_wing andwall_slip.

4. Click on the Mask tab, click on the 1 in the row 3D elements to display only volumeelements.


6. Click on the elem s button and select displayed.

7. Click the dest com ponent button and select the component fluid.


9. In the Mask tab, click on the 1 in the row 2D elements to display only shell elements.

10. Click Mesh > Delete > Elem ents.



11. Click on the elem s button and select displayed.

12. Click delete entity and then click return.

13. In the Model Browser, right-click on fluids and select Make C urrent, and then right-click on it again and select Show.


15. Click the com ps button and select the fluid component. Click find faces and then clickreturn to close the panel.

16. A new component named f̂aces is created and displayed in the Model Browser. Right-click on it and select Isolate.


18. Select the elements lying on the inflow boundary, and move them to the inflowcomponent. The easiest way to do this is to select a single element on the inflowboundary and then select by face from the extended entity selector. Repeat this stepselecting the elements on the outflow boundary, and moving them to the outflowcomponent.



Inflow boundary selected for the inflow component

19. Move the shell elements from the four other sides to the component wall_slip.

20. Move the shells on the wing profile to the wall_wing component. Click return to closethe panel.

21. The collector f̂aces should now be empty and can be deleted by right-clicking on it inthe Model Browser.

22. Delete the other empty components - plane, box, BL_thin, CFD_bl001 andCFD_tetcore001.

Step 9: Export the model

1. Right-click on C om ponents in the Model Browser and select Show.

2. Click on the Export Solver Deck icon and export the model for the CFD solver of yourchoice.



CFD-1700: Mapping CFD Results

This exercise will cover how to take results from a CFD analysis and apply them to a newmodel for heat transfer or structural analysis. Using the linear interpolation tools withinEngineering Solutions, results from a CFD analysis can be transferred to be loads in ananalysis to be run in OptiStruct or any other supported solver.

Typically, scalar results such as temperatures or pressures are mapped. Results must be in aTecplot file (*.tpl or *.dat). This exercise will demonstrate how Engineering Solutions has a

very easy and straightforward way to transfer loads from CFD to a heat transfer of structuralanalysis.

Step 1: Open model file

1. Click the Open .hm file icon .

2. Select the file \tutorials\hm\s_bend_tube.hm.

3. Click Open.

4. Use the Model Browser to turn off the display of the component cube.

5. From the menu bar, select Preferences > User Profiles.



8. Click OK.

Step 2: Load and process Tecplot file

1. From the menu bar, select Tools > Mapping C FD Loads.



2. This opens a message window explaining the mapping process and asking if you want tocontinue. Select Yes.

3. Browse and select the file Sbend_Model_CFDpp_Tecplot_SURFTEC.DAT.

4. Select Open to open the file.

5. This opens the file and creates nodal results files for each result type present in the file.

6. Another message appears telling you that the file names can be reviewed in the log reportwindow. Click OK to close the window.

7. Review the log file. Notice that for each scalar data type available in the Tecplot file, a

new file was created. The file name is appended with the name of the scalar and“_for_LI”. When you have finished reviewing the file, click Dism iss.



Step 3: Create a load collector for the pressure loads

1. Right click in the Model Browser and select C reate > Load C ollector.

2. For Name: enter pressure.

3. For the Color: select any color.

4. Select C reate to complete the creation of the load collector.

Step 4: Map the load pressure to the new file



1. Select Tools>Linear interpolation>Pressure.

2. Click on elem s and select displayed to select all the displayed elements.

3. Click on the switch next to magnitude and select linear interpolation.

4. There is now a file= field under linear interpolation. Click on the next to the file=field to select a file.

5. Browse for the file Sbend_Model_CFDpp_Tecplot_SURFTEC_P_for_LI.DAT. Click Open.

This file contains the pressure results from the CFD analysis.

6. For search radius, enter 0.05.

The search radius is a search distance to find the loads which are within that distancefrom a centroid or node on which a load is being interpolated. HyperMesh uses the nearestthree loads located within that distance to create the load at the centroid or node bylinear interpolation. Linear interpolation uses a triangulation method, so if it finds fewerthan three loads within that distance no interpolation takes place. While reading the initialloads from a file, if linear interpolation is not possible because the search radius is toosmall, the original loads are simply applied to the nearest centroid or node.

7. Next to nodes on face, click on nodes and then select three nodes that define anelement (see image below).

8. Select create.



9. Select return to exit the panel.

Step 5: Turn off the display of the load collector and show pressureloads as a contour plot

1. Within the Model Browser, expand the folder Load Collector.

2. To turn off the display of the load collector pressure, click on the m esh icon, , to theleft of pressures. The icon will be greyed out and the pressure loads will no longer bedisplayed.

3. Select Tools > C ontour Loads.

This opens a new tab called Contour Loads.

4. Click on pressures to select the load collector to be contoured.

5. Click on Accept.

This displays the Contour panel and automatically loads the appropriate information.

6. Click on contour.



This simply displays the pressure load as a contour for an easier way to view the load. Nowthat the pressure load has been applied, an additional analysis can be setup and run.



CFD-1800: Using HyperMesh, AcuSolve and HyperView toPerform a CFD Analysis

This tutorial uses:

HyperMesh (for meshing the CFD model)

AcuConsole (for setting up the model and submitting the job)

AcuSolve (for running the CFD simulation)

HyperView (for post processing)

This tutorial uses the same model file used by CFD-1000 of online HyperWorks tutorials.

Exercise 1: Launch HyperMesh

Step 1: Launch HyperMesh and open the model file


2. Select manifold_surf_mesh.hm from the tutorial directory.

3. Click Open to load the .hm file containing the surface mesh.

Step 2: Load the AcuSolve User profile

1. Click Preferences > User Profiles.




3. Select the radio button C FD.

4. Select AcuSolve from the drop down list next to it.

5. Click OK.

Step 3: Check that all the elements in the collectors wall, inlet and outletdefine a closed volume

1. Click Mesh > C heck > C om ponent > Edges to open the Edges panel.

2. Click the yellow comps button and select the collectors wall, inlet and outlets.

3. Click se lect, and then click find edges.


4. Toggle the free edges button to T-connections.

5. Select the three components again and then click find edges.

The status bar will display "No T -c onnec ted edges w ere found."


Step 4: Create the CFD Mesh

1. Click Mesh > Volum e Mesh 3D > C FD tetram esh to open the CFD Tetramesh panel.

2. Select the Boundary se lection subpanel.

3. Under the heading With BL (fixed), click com ps and select the collector wall.


5. Verify that the switch below the W/o BL (float) selector is set to Remesh. This meansthat the meshes in the zones defined by collectors inlet and outlets will be remeshedafter being deformed by the boundary layer growth from adjacent surface areas.





8. Select the options to specify the boundary layer and the tetrahedral core:

Number of Layers= 5

First layer thickness= 0.5

BL growth rate= 1.1

9. Under the BL hexa transition mode header, verify that the selection is set to Tetra toall Layers.

This uses tetrahedral elements for the boundary layers.


This option generates the boundary layer alone and stops before generating thetetrahedral core.



13. Set the tetrahedral core growth rate, Interpolate. This avoids the problem of generatingtetrahedral elements that are too large at the center of the core mesh.

14. Click m esh to create the CFD mesh. When this task is finished, two collectors areautomatically created: CFD_bl001 and CFD_tetcore001.


Step 5: Visualize and Mask the generated Mesh

1. To visualize the new mesh, set the element display to off for wall, inlet and outletscollectors.



2. To mask the generated mesh use the shortcut key F5 and select the elements to bemasked.

The following is a snapshot. Observe the excellent mesh quality.

Step 6: Organize the model

1. Rename the collector CFD_Tetramesh_core as fluid. This collector will hold all the 3-Dvolume elements.

2. Click BC s>Organize to move all the elements from the collector CFD_boundary_layerto collector fluid.

3. Click BC s>Faces to automatically generate the collector f̂aces containing all theexternal faces of the elements in collector fluid.

4. Click BC s>C om ponent>Single to create two new components named inflow andoutflow.



5. In the Model Browser, put On the display f̂aces component and put off the fluidcomponent.

6. Click BC >s Organize and click one element on the inlet/inflow plane (the element willbecome highlighted).

7. Click elem s>by face. All the elements in the collector f̂aces on the inlet/inflow planewill be selected.

8. Set the dest comp as inflow, and click m ove. Similarly, move the elements from f̂acesassociated with the outlets to the collector outflow.

9. Show the inflow and outflow components in the Model Browser.

When done, you will have all the exterior surfaces colored according to the collectorswhere they have been placed as shown in the image.



10. The remaining elements in the collector f̂aces are the walls. Rename collectors f̂acesto walls.

Step 7: Exporting model to AcuConsole

1. Display only the components containing elements that have to be exported forAcuConsole. The components are: fluid, inflow, outflow, and walls. All othercomponents should not be visible.

2. Click the AcuC onsole icon in the CFD toolbar to open the AcuSolve dialog.

3. In the File field, click on the file icon and specify a name and location for the file.



4. Click Export to launch AcuConsole and export a file.

Exercise 2: Launch AcuConsole

The AcuConsole GUI opens with the model loaded.

Step 1: Visualizing the model in AcuConsole



1. Expand Surfaces and right click on Display Type to select solid & wire. This updatesthe model display with a mesh in the Visualization area.

2. For changing the color of a surface, right-click on the surface and click Display C olor.Select the desired color from the Select color dialog.

Step 2: Set Problem description and Solution Strategy

1. Double click on Problem Description under Global.

2. In the panels area set the Title to Demo and Turbulence equation to Spalart-Allm aras.



3. Double-click on Auto Solution Strategy and set the Relaxation factor to 0.4.

Step 3: Set Nodal Initial Condition and Material model

1. Double click on Nodal Initia l C ondition under Global.

2. In the panels area set the X velocity to 2.0. Therefore, at the start of the simulation

fluid is flowing with a velocity of 2 m/s.



3. In Model > Volumes > fluid tet4 > Element Set double click on Elem ent Set andselect W ater in the drop down list next to Material model.

Step 4: Set Boundary Conditions

1. Right click on Surfaces and select Surface Manager. The Surface Manager dialogopens.

2. Make sure the Simple BC Active and Simple BC Type columns are present. If they arenot shown click on the C olum ns button and select them.

3. Under the Simple BC Type, make sure Inflow is set for fluid tet4 inflow tria3 surface,Outflow for fluid tet4 outflow tria3 and Wall for fluid tet4 walls tria3.



4. Click the C lose button to close the dialog.

Step 5: Set Inlet Velocity 1. Double click on Surfaces > fluid tet4 inflow tria3 > Sim ple Boundary C ondition.

2. In the panel area, select Inflow Type to Average velocity and Average velocity to2.0 m/s.

Step 6: Launch AcuSolve

1. Click on Tools in the menu bar and select AcuSolve from the list to open the LaunchAcuSolve dialog.



2. Set the Problem name, Problem directory, Working directory, Number ofprocessors, etc. in this dialog. Click the OK button to launch AcuSolve.

When the job is submitted, AcuRun executes AcuPrep followed by AcuSolve.

AcuPrep reads the input file and prepares the data for AcuSolve to compute thesolution.

The AcuTail window shows the status of the job.



AcuProbe can be used for monitoring the job.



Step 7: Launch AcuOut

AcuOut is a tool used to translate AcuSolve solution output to other formats. In thisworkshop the output has to be converted to EnSight format for loading to HyperView.

1. Click on Tools > AcuOut from the menu bar. The AcuOut GUI opens.

2. Set the Output format to EnSight. Set the Data type, Variables, Time steps andformat. Click the Do button next to Process.

Exercise 3: Launch HyperView

Step 1: Launch HyperView

HyperView can be launched several ways including:

Click on Applications > HyperView from the HyperMesh menu bar.

On Windows machine, click on Start > Alta ir HyperW orks 12.0 > HyperView.

On LINUX machine, type hv in terminal window.

1. Click on the button next to Load model and Load results. Provide the location of casefile generated using AcuOut.



2. Click Apply to load the model into HyperView.

Step 2: Boundary Surface

The model is colored by geometry after loading.

1. To color it by a scalar quantity, click the C ontour panel button on the Resulttoolbar.

2. Select Pressure as the Result type and click Apply.

Step 3: Cut Plane

1. Right-click within the Results Browser and select C reate > Section C ut.



A section cut is automatically applied to the model, and the Section Cut panel isdisplayed.

2. Verify that Define plane is set to Z Axis. Click Apply.

3. Verify that Display Options has the Cross section option turned on. You can use theDefine plane slider bar (located under the Z Axis button) to move the position of thesection cut.

4. Click the C ontour panel button on the Result toolbar.

5. Select Velocity (v) as the Result type and click Apply.

Step 4: Slice (or) Clipping plane

1. Within the Results Browser expand the Section Cuts folder, right-click Section 1, andselect Edit. The Section Cut panel opens.

2. Under Display options select C lipping plane.



Step 5: Velocity vectors

1. In the Section Cut panel (under Display options) set it back to Cross section.

2. Click the Vector panel button on the Result toolbar.

3. Under Selection (from the drop down list) select Sections.

4. Click Sections to open the Extended Entity Selection. Select Displayed.

5. Select x & y component and click Apply.



Step 6: Streamlines

1. Within the Results Browser, expand the Section Cuts folder. Click on the icon beforeSection 1 to put off the display.

2. Using the Results Browser, turn off display for all components.

Only turn On the display for SBC: fluid tet4 inflow tria3 and SBC: fluid tet4 outflowtria3 so that the inside of the flow domain is displayed in the graphics area.

3. Click the Stream lines panel button from the Result toolbar to enter the Streamlinespanel.

4. Click Add to add a new set of steamlines.

5. Set the Rake type to Line.

6. Click on the button.

This opens the Reference point dialog. Enter the Reference points as (X1: 66.96, Y1:79.69, Z1: -400) and (X2: 28.9, Y2: 79.69, Z2: -400).



7. Enter 35 into the Number of seeds text box.

8. Select Downstream from the Integration mode drop-down menu.

9. Click the C reate Stream lines button (located in the lower right hand corner of thepanel.)

10. Under Display options, change the Streamline size to 4 and hit Enter on the keyboard.

11. Activate the Draw as tube option.



Crash

The following tutorials are available for the Crash - LS-DYNA user profile:

CRASH-1000: Defining LS-DYNA Model and Load Data, Controls and Output

CRASH-1100: Using Curves, Beams, Rigid Bodies, Joints and Loads in DYNA

CRASH-1200: Model Importing, Airbags, Exporting Displayed,and Contacts using DYNA

CRASH-1300: Rigid Wall, Model Data, Constraints and Output Using DYNA

The following tutorials are available for the Crash - RADIOSS user profile:

CRASH-2000: Front Impact Bumper Model

CRASH-2100: Simplified Car Pole Impact



CRASH-1000: Defining LS-DYNA Model and Load Data,Controls, and Output


View DYNA keywords in the Engineering Solutions - Crash – LS-DYNA user profile asthey will appear in the exported DYNA input file

Understand part, material, and section creation and element organization

Create sets

Create velocities

Create nodal single point constraints

Create contacts

Define output and termination

Export models to LS-DYNA formatted input files

Exercises

This tutorial contains the following exercises:

Exercise 1: Define Model Data for the Head and A-Pillar Impact Analysis

Exercise 2: Define Boundary Conditions and Loads for the Head and A-Pillar Impact Analysis

Exercise 3: Define Termination and Output for the Head and A-Pillar Impact Analysis

Section 1: Define Model Data

Relation of *PART, *ELEMENT, *MAT, and *SECTION to Each Other

*ELEMENT EID PID

*PART PID SID MID

*SECTION SID

*MAT MID

A *PART shares attributes such as section properties (*SECTION) and a material model



(*MAT). A group of elements (*ELEMENT) sharing common attributes generally share acommon part ID (PID). The figure below shows how the keywords *PART, *ELEMENT, *MATand *SECTION relate to each other. A unique PID assigns a material ID (MID) and a section ID(SID) to an element.

The figure below shows how the keywords *ELEMENT, *PART, *SECTION, and *MAT areorganized.

*ELEMENT EID PID Elements are organized into a componentcollector.

*PART PID SID MID Component collector’s card image.

*SECTION SID Property collector with a property cardimage. Assign a property to a *PART bypointing to the property collector in thecomponent collector’s card image.

*MAT MID Material collector with a material cardimage. Assign the material to the *PARTby associating the material collector tothe component collector.

Component, property and material collectors are created and edited from the Collectorspanel.

View DYNA Keywords in Engineering Solutions

An Engineering Solutions card image allows you to view the image of keywords and data linesfor defined DYNA entities as interpreted by the loaded template. The keywords and data linesappear in the exported DYNA input file as you see them in the card images. Additionally, forsome card images, you can define and edit various parameters and data items for thecorresponding DYNA keyword.

Card images can be viewed using the Card Editor panel which can be access from the CardEditor icon in the toolbar, or from the right-click context menus in the Model Browser andSolver Browser.

Create *MAT

In Engineering Solutions, a *MAT is a material collector with a card image. To relate it to a*PART, the material collector is associated to a component collector. A material collector canbe created from the Model Browser, Solver Browser or by selecting the Model menu andchoosing Materia l > C reate.

Update a Component’s Material

Update any component with any material from the Component Collectors panel, updatesubpanel.

Material Table Utility

This utility allows you to do the following:



View a list of all existing materials in the model and attributes for them.

Create, edit, merge and check for duplicate materials.

This utility is located in the the Model menu.

Create *SECTION

In Engineering Solutions, *SECTION is a property collector with a card image. This is createdin the Property Collectors panel, create subpanel.

Exercise 1: Define Model Data for the Head and A-Pillar Impact Analysis

The purpose for this exercise is to help you become familiar with defining LS-DYNA materials,sections and parts using Engineering Solutions – Crash - LS-DYNA.

This exercise comprises of setting up the model data for an LS-DYNA analysis of a hybrid IIIdummy head impacting an A-pillar. The head and A-pillar model is depicted below.

Head and A-pillar model

This exercise contains the following tasks.

Define the material *MAT_ELASTIC for the A-pillar part and head part.

Define *SECTION_SHELL for the A-pillar.

Define *SECTION_SOLID for the head.

Define *PART for the A-pillar and the head.

Step 1: Load the Crash - LS-DYNA user profile

1. From the startup menu, choose Engineering Solutions > C rash >HyperMesh.



2. Select the LS-DYNA profile in Crash and click OK.

Step 2: Retrieve the model file

1. From the toolbar, click the Open Model icon and browse to the file head_start.hm.

2. Click Open.

The model loads into the graphics area.

Step 3: Define the material *MAT_ELASTIC for the A-pillar and head

1. Right-click in the Model Browser and select C reate > Materia l.

The Create material dialog opens.

2. For Name, enter elastic.

3. For Card image, select MATL1.

4. Click C ard edit m ateria l upon creation to activate the option.

5. Click C reate to create the material and edit its card image.

6. Click the [Rho] field and enter 1.2 E-6 for the density.

7. For Young’s modulus [E], specify 210.

8. For Poisson’s ratio [Nu], specify 0.26.

9. Click return to exit the panel.

Step 4: Define property (*SECTION_SHELL) with a thickness of 3.5 mmfor the A-pillar



1. Right click in the Model Browser and select C reate > Property.

The Create property dialog opens.

2. For Name, enter section3.5.

3. In the Type field, select SURFAC E.

4. For Card image, select SectShll.

5. Click C ard edit property upon creation to activate the option.

6. Click C reate to create the property and edit the card.

7. For T1, enter 3.5.


Step 5: Define *SECTION_SOLID for the head


2. For the Name field, type solid.

3. In the Type field, select VOLUME.

4. For Card image, select SectSld.

5. Click C ard edit property upon creation to deactivate the option.

6. Click C reate to create the property.

Step 6: Define *PART for the A-pillar

MAT_ELASTIC is the material collector named "elastic". *SECTION_SHELL is the propertycollector named "section3.5".

1. Right click on the pillar component in the Model Browser and select Edit.

2. For Card image, select Part.

3. Click the Materia l tab.

4. Click the Assign m ateria l option to activate it.

5. For Name, select elastic.

6. Click the Property tab.

7. Click Assign property to activate the option.

8. For Name, select section3.5.

9. Click Update.



Step 7: Define *PART for the head

*MAT_ELASTIC is the material collector named "elastic". *SECTION_SOLID is the propertycollector named "solid".

1. Right click on the component head in the Model Browser and select Edit.

2. For Card image, select Part.

3. Click the Materia l tab.

4. Click the Assign m ateria l option to activate it.

5. For Name, select elastic.

6. Click the Property tab.

7. Click the Assign property option to activate it.

8. For Name, select solid.

9. Click Update to update the component.

The exercise is complete. Save your work to as an .HM file.

Section 2: Define Boundary Conditions and Loads

*SET

With the exception of *SET_SEGMENT, all *SET types are created from the Entity Setspanel, from clicking Tools > C reate > Sets. Graphically view a set’s contents with thereview function in the Entity Sets panel. *SET_SEGMENT is created from the Contactsurfspanel and is discussed in this chapter.

Exercise 2: Define Boundary Conditions and Loadsfor the Head and A-Pillar Impact Analysis

The purpose for this exercise is to help you start becoming familiar with defining LS-DYNAboundary conditions, loads and contacts using Engineering Solutions.

This exercise comprises of setting up the boundary conditions and loads data for an LS-DYNAanalysis of a hybrid III dummy head impacting an A-pillar. The head and A-pillar model isdepicted below.




This exercise contains the following three tasks.

Define velocity on all nodes of the head with *INITIAL_VELOCITY

Constrain the pillar’s end nodes in all six degrees of freedom with*BOUNDARY_SPC_NODE

Define a contact between the head and A-pillar with*CONTACT_AUTOMATIC_SURFACE_TO_SURFACE

Step 1: Make sure the LS-DYNA user profile is still loaded

1. From the menu bar, click Preferences > User Profiles.

2. Select Engineering Solutions >C rash> LS-DYNA.

Step 2: Retrieve the model file head_2.hm

1. Retrieve the model file head_2.hm.

2. Take a few moments to observe the model using various visual options available (rotation,zooming, etc.).

Step 3: Create a node set containing all the nodes in the headcomponent



1. Click Model > Sets > Nodes > C reate.

2. For Name, enter Vel_Nodes.

3. For Card image, select Node.

4. With the nodes selector active, click nodes >> by collector and select the componenthead.

5. Click create to create the set.


Step 4: Define the initial velocity

1. Click BC s > Initia l Ve locity > Node Set > C reate.

2. For loadcol name, enter init_vel.

3. Click create/edit to create the load collector and edit its card image.

4. In the node set ID [NSID] field, select the entity set Vel_Nodes.

5. For the initial velocity in the global x-direction, VX field, specify 5.

6. Click return.

7. Stay in the Load Collector panel for the next step.

Step 5: Create a load collector for the constraints to be created

1. In the Load Collector panel, in the Name field, enter SPC.

2. For creation method, select none.

3. Click create to create the load collector.


Step 6: Create constraints on the pillar’s end nodes

1. Click BC s > C onstra ints > Nodes > C reate.

2. Leave the entity selector set to nodes.

3. Click nodes >> by sets and select the pre-defined entity set nodes for SPC.

Notice the nodes at the pillar’s ends are highlighted.

4. Leave all six degrees of freedom, dof1 thru dof6, active.

5. Leave the load type as BoundSPC.

6. Click create to create the constraints.




Step 7: Define a *SET_SEGMENT for the slave entities, the A-pillarelements

1. Click Model > Segm ents > Segm ent > C reate.

2. For name, type pillar_slave.

3. Optionally select a color for the contactsurf.

4. With the elems selector active, click elem s >> by collector and then select the pillarcomponent.

5. Click create to create the contactsurf.

6. Review the contactsurf to make sure its pyramids are pointing out of the pillar.

7. Stay in this panel for the next step.

Step 8: Define a *SET_SEGMENT for the master entities, the headelements

1. Select the solid faces subpanel.

2. For name, type headmaster.

3. For Card image, select setSegm ent.


5. With the elems selector active, click elem s >> by collector and then select the headcomponent.

6. Leave the toggle set to nodes on face.

7. Click the yellow nodes selector to make it active.

8. Select three nodes belonging to the same face of a solid element.

9. For the break angle, leave it set to 30.


11. Review the contactsurf to make sure its pyramids are pointing out of the head.


Step 9: Create SurfaceToSurface contact interface between pillar andhead

1. Click BC s > C ontact > Surf to Surf > C reate.

2. For Name, type contact.



3. Leave Type set to SurfaceToSurface.

4. Click create to create the group.

5. Stay in the Interfaces panel for the next step.

Step 10: Add the slave and master contactsurfs to the group

1. Select the add subpanel.

2. For the master type, select csurfs.

3. Click the contactsurfs selector and select the headm aster contactsurf.

4. Click update in the master: line, to the right of the yellow contactsurfs selector.

5. For the slave type select csurfs.

6. Click the contactsurfs selector in the slave: line and select pillar_slave.

7. Click update in the slave: line.


Step 11: Edit the group’s card image to define the AUTOMATIC option

1. Select the card im age subpanel.

2. Click edit to edit the group’s card image.

3. Under Options, click the toggle to select Autom atic.

4. Click return to go back to the Interfaces panel.


Step 12: Review the group’s master and slave surfaces


2. For name, select contact.

3. Click rev iew.

4. Notice the master and slave entities are temporarily displayed blue and red, respectively.


The exercise is complete. Save your work to a HyperMesh file.



Exercise 3: Define Termination and Output for theHead and A-Pillar Impact Analysis

The purpose for this exercise is to help you become familiar with defining LS-DYNA controldata and output requests using Engineering Solutions.

This exercise comprises of defining the termination and output for an LS-DYNA analysis of ahybrid III dummy head impacting an A-pillar. The head and A-pillar model is shown in theimage below.


This exercise contains the following four tasks.

Specify the time at which LS-DYNA is to stop the analysis with*CONTROL_TERMINATION

Specify ASCII output with *DATABASE_(Option) cards

Specify the output of d3plot files with *DATABASE_BINARY_D3PLOT

Export the model to an LS-DYNA 971 formatted input file

Step 1: Make sure the Crash - LS-DYNA user profile is still loaded

Step 2: Retrieve the model file head_3.hm



Step 3: Specify the time at which you want LS-DYNA to stop theanalysis with *CONTROL_TERMINATION

1. Click Model > C ontrol C ards to open the Control Cards panel.

2. Click next to scroll through the list.

3. Select C ONTROL_TERMINATION.

A card image pops up.

4. For the termination time of the analysis, ENDTIM, specify 2.5.

5. Click return to go back to the Control Cards panel.

Step 4: Specify frequency for animation file output

1. Click Output > Database_Binary > D3PLOT.

2. For the interval between outputs in the D3PLOT file, [DT] field, specify 0.1.


Step 5: Specify frequency for ASCII of time history file output

1. Click Output > Database_Extent > Binary.

2. For the GLSTAT file, [GLSTAT] field, specify 0.1.

This specifies the output of global data at every 0.1 ms.

3. For the MATSUM file, [MATSUM] field, specify 0.1.

This specifies the output of material energies every 0.1 ms.

4. For the SPCFORC file, [SPCFORC] field, specify 0.1.

This specifies the output of SPC reaction forces every 0.1 ms.



Step 6: Export the model as an Ls-Dyna keyword file

1. Click File > Export > Solver Deck to open the Export tab.

2. Make sure LS-DYNA is selected as the File type and the appropriate template isselected.

3. Enter the file name as head_complete.key.

4. Click Export.



Step 7 (Optional): Submit the LS-DYNA input file to LS-DYNA 971

1. From the desktop’s Start menu, open the LS-DYNA Manager program.

2. From the solvers menu, select Start LS-DYNA analysis.

3. Load the file head_complete.key.

4. Click OK to start the analysis.

Step 8 (Optional): Post-process the LS-DYNA results using HyperView

The exercise is complete. Save your work to an .HM file.

Go to HyperMesh Tutorials



CRASH-1100: Using Curves, Beams, Rigid Bodies Joints,and Loads in LS-DYNA

In this tutorial, you will learn how to:

Create XY curves to define non-linear materials

Define beam elements

Create constrained nodal rigid bodies

Create joints

Define *DEFORMABLE_TO_RIGID

Define *LOAD_BODY

Define *BOUNDARY_PRESCRIBED_MOTION_NODE

Use the Component Table tool to review the model’s data

Tools

The following tools are covered in this tutorial:

DYNA Tools

Component Table

Curve Editor

The Component Table is part of the Model menu. With this tool, you can view a summary ofthe model’s parts as well as create and edit parts. Below is a list of the tool's functionality.

Create a list of displayed or all parts and view them in the graphics area

Display parts with same section or material

Rename and renumber parts, sections and materials

Update thickness

Create new parts

Assign sections and materials to parts

Export table to file with comma separated format

In the Component Table window, place the cursor over each button to see an explanationof each button.

Below is a sample image of the Component Table.



The Curve editor can be accessed by clicking Model > Function > C reate C urve from themenu bar.

The Curve editor is a pop-up window that allows you to view and modify graphed curves in amore intuitive and holistic way than the individual xy plots panels provide.

Below is a list of the tool’s functionality.

Change curve attributes

Change graph attributes

Display curves in the graph area

Create a new curve

Delete a new curve

Rename a curve

Below is a sample image of the Curve editor.



Exercises

This tutorial contains the following exercises:

Exercise 1: Define Model Data for Seat Impact Analysis

Exercise 2: Define Boundary Conditions and Loads for the Seat Impact Analysis

Exercise 1: Define Model Data for the Seat ImpactAnalysis

This exercise will help you continue to become familiar with defining LS-DYNA model datausing Engineering Solutions.

This exercise is comprised of defining and reviewing model data for an LS-DYNA analysis of avehicle seat impacting a rigid block. The seat and block model is shown in the image below.



Seat and block model

Step 1: Load the LS-DYNA user profile

1. From the startup menu, select Engineering Solutions > C rash > HyperMesh.

2. Select the LS-DYNA profile in Crash and click OK.


1. Browse to the file seat_start.hm.

2. Take a few moments to observe the model using various visual options available inHyperMesh (rotation, zooming, etc.).

Step 3: Create an xy plot

1. Click Model > Functions > C reate > Plot.

2. For plot=, enter seat_mat.

3. Verify the plot type is set to standard.

4. Leave the like = field empty.

When an existing plot is selected, the new plot adopts its attributes.

5. Click create plot.

6. Click return.

Step 4: Input data from a file to create two stress-strain curves

1. Click Model > Functions > C reate > Read C urves.

2. For plot =, leave it set to seat_mat.

3. Click browse... and locate the file named seat_mat_data.txt.



4. Click input to input the file.

5. Notice two curves are created and are named 0.001 strain rate for steel (curve1) and0.004 strain rate for steel (curve2).

6. Click return.

Step 5: Create a table

1. From the Model menu, click Table > C reate.

2. Enter Steel_flow_stress_data as a name for the table.

3. In the card image, in the [ArrayCount] field, specify 2.

This is the number of strain rate values to be specified.

4. For the strain rate VALUE(1) field, specify 0.001.

5. For the strain rate VALUE(2) field, specify 0.004.

6. Click on C urveId(1) and select curve1.

7. Click on C urveId(2) and select curve2.


Step 6: Create the non-linear material(*MAT_PIECEWISE_LINEAR_PLASTICITY)

1. Click View > Browsers > HyperMesh > Solver to open the Solver Browser.

2. Right-click anywhere in the Solver Browser and click C reate > *MAT > MAT (1-50) >24-*MAT_PIEC EW ISE_LINEAR_PLASTIC ITY.

3. For Name: type steel.

4. Set Type = Elastic-Plastic.

5. Set Card image = MAT_24 and click OK.

6. For density [Rho] field, specify 7.8 E-6.

7. For Young’s Modulus [E] field, specify 200.

8. For Poisson’s ratio [NU] field, specify 0.3.

9. For yield stress [SIGY] field, specify 0.25.

10. For the *DEFINE_TABLE id [LCSS] field, select curve3 (id=5).

11. Click return to close the card image.

Step 7: Update the base_frame and back_frame components with the



new non-linear material

1. Click Model > C om ponent Table.

2. From the Table menu, click Editable.

3. Select the components base_fram e by clicking on its row to highlight it.

4. For Assign Values:, select Materia l nam e.

5. For HM-Mats:, select stee l.

6. Click Set and click Yes to confirm.

7. Repeat steps 3 - 6 for the component back_frame.

8. Close the Component Table.

Steps 8-10: Create a beam element to complete the seat’s back_frameconnection to the side_frame on the left side

Step 8: Restore a pre-defined view

1. On the toolbar, click the User Views icon.

A dialog opens.

2. Click restore1 to see the beam view.

Step 9: Set the current component to beams

1. In the Model Browser, right-click on the beam s component and select Make C urrent toset the beam component as the current collector.

Step 10: Create the beam

1. Click Mesh > C reate > 1D Elem ents > Bars to open the panel.

2. Click the leftmost switch and select node.

A direction node is selected later to define the beam’s section orientation.

3. Click the Node A selector to make it active.

4. Select the center node of the left nodal rigid body for Node A.

Node B is active now.

5. Select the center node of the right nodal rigid body for Node B.

6. Select any non-center node of one of the nodal rigid bodies for the direction node.



Notice the beam is created.


Step 11: Display node IDs for ease of following the next steps

1. Click on the num bers icon to open the Numbers panel.

2. Change the entity selector set to nodes.

3. Click nodes and select by id. Enter 425-427, 431 and press Enter.

4. Activate the display checkbox, and click on to display the IDs.

5. Click return.

Step 12: Set the current component to w elding

1. In the Model Browser, right-click on the welding component and select Make C urrentto set the welding component as the current collector.

Step 13: Create the rigid connection between nodes(*CONSTRAINED_NODAL_RIGID_BODY)

1. Click C onnections > Nodal Rigid Body > C reate.

2. Set nodes 2-n to m ultiple nodes.

3. Select the beam’s free end for node1.

4. Select nodes 425, 426, 427 and 431 for nodes 2-n.

5. Leave the attach nodes as set option active.

6. Click create to create the nodal rigid body.

7. Click return.

A *CONSTRAINED_JOINT_STIFFNESS is not created; it is not needed for this joint towork.

Step 14: Display node IDs for ease of following the next steps

1. Click on the num bers icon to open the Numbers panel.

2. Leave the entity selector set to nodes.

3. Click nodes and select by id. Type 1635, 1636 and press Enter.

4. Activate the display checkbox, and click on to display the IDs.



5. Click return.

6. From the toolbar, click the W irefram e Elem ents (Skin Only) icon to change tostandard graphics mode.

Step 15: Activate coincident picking

1. Click Preferences > G raphics.

2. Activate coincident picking.

3. Click return.

Step 16: Set the current component to joint

1. In the Model Browser, right-click on the joint component and select Make C urrent toset it as the current collector.

Step 17: Create a revolute joint between two nodal rigid bodies(*CONSTRAINED_JOINT_REVOLUTE)

The rigid bodies must share a common edge along which to define the joint. This edge,however, must not have the nodes merged together. The two rigid bodies will rotate relativeto each other along the axis defined by the common edge.

1. Click C onnections > Joints > Elem ent > C reate.

2. Set the joint type to revolute.

node1 is active.

3. Click on node 1635.

Notice the coincident picking mechanism displays two nodes – 1635 and 1633.

4. Move the mouse to node 1635 in the coincident picking display and click on it to select itfor node 1 in rigid body A.

node2 is now active.

5. Click on node 1635 again to see the coincident picking mechanism and select node 1633for node 2 in rigid body B.


6. Click on node 1636.

Two coincident nodes are displayed – 1636 and 1634

7. Select node 1636 for node 3 in rigid body A.


8. Select node 1634 for node 4 in rigid body B.



9. Click create to create the joint.

10. Click return.

Steps 18-20: Define *DEFORMABLE_TO_RIGID to set up the movingseat as rigid until the time of impact with the block, to reducecomputation time

Step 18: Create an entity set that contains the components base_frame, back_frame, and cover

1. Click Model > Sets > Part > C reate.

2. For name =, enter set_part_seat.

3. For card image, select Part.

Notice the entity selector is set to comps.

4. Click the yellow com ps button and select the base_fram e, back_fram e and covercomponents.


6. Click return.

Step 19: Define *DEFORMABLE_TO_RIGID to switch the deformableseat to rigid at the beginning of the analysis

1. Right click in the Solver Browser and select C reate > *DEFORMABLE_TO_RIG ID >*DEFORMABLE_TO_RIG ID.

2. For Name:, enter dtor and click OK to create the card.

3. Click the part set ID, [PSID] button twice and select set_part_seat.

4. Click the master rigid body, [MRB], button twice and select back_fram e.

5. Click return.

Step 20: Create *DEFORMABLE_TO_RIGID_AUTOMATIC to switch therigid seat to deformable when contact between the seat and block isdetected

1. Right click in the Solver Browser and select C reate > *DEFORMABLE_TO_RIG ID >*DEFORMABLE_TO_RIG ID_AUTOMATIC.

2. For Name:, type dtor_automatic and click OK to create the card.

3. For the unique set number for this automatic switch set, [SWSET], enter 1.



4. For the activation switch code [CODE] select 0.

The switch will take place at [TIME1].

5. For [TIME1] enter 175.

The switch will not take place before this time.

6. Activate R2D_Flag in the menu area.

On export, the number of rigid parts to be switched to deformable is written to the R2Dfield (card 2, field 6). This number is based on the number of parts in the entity set youselect next.

7. Move the scroll bar on the left side of the card image down to see [PSIDR2D].

8. Click the [PSIDR2D] button twice and select set_part_seat.

9. Click return.

Steps 21-25: Review the model’s component data using the ModelBrowser, Solver Browser or Component Table tool

Using the Model Browser approach:

Step 23: Display only parts with a particular material (Ex: steel)

1. In the Model Browser, click on the Materia l View icon .

2. Highlight the material steel, then right click on it and choose isolate to see onlycomponents that have the selected material assigned.

3. To review several materials, click on the isolate icon then select a material and scrollthrough the material using the arrow keys in the model browser. The corresponding partsare automatically isolated in the view.

4. Follow the above steps to select components using the By Properties option.

Step 24: Display all components

1. In the Model Browser, click on the Materia l View icon .

Step 25: Rename a part

1. In the Model Browser, click on the C om ponent View icon .

2. Select the part to rename and right click on it. Choose renam e from the extended menuoptions and the becomes editable to enter a new name.



Notice the part's new name in the Solver and Model Browser.

Step 26: Renumber a part ID

1. In the Model Browser, right-click on the Part ID field.

2. Enter a number that does not conflict with the existing part IDs.

3. Click Yes to confirm.

Using the Solver Browser approach:


1. Expand the Materials folder to see all available materials in the model.

2. Right-click on the material Stee l and select Isolate from the menu.

3. Complete steps 1 and 2 to select components based on properties using the *sectionfolder.


1. In the Solver Browser, click on the Materia l View icon .


1. In the Solver Browser, click on the C om ponent View icon .

2. Select the part to rename and right click on it. Choose renam e from the extended menuoptions and the becomes editable to enter a new name.



1. In the Model Browser, right-click on the Part ID field.

2. Enter a number that does not conflict with the existing part IDs.


Using the Component Table approach:




1. Click Tools > C om ponent Table.

2. From the Display menu, click By Materia l.

3. Select material stee l and click proceed.

Notice that the GUI and the Component Table show only those components withmaterial steel assigned. All other components get turned off.

5. Follow the above steps to select components using the By Properties and By thicknessoption.


1. From the Display menu, click All.

2. Notice now that the GUI shows all components of the model.


1. From the Table menu, click Editable to make the table editable. (All columns with a whitebackground can be edited. Ex: Part name, Part id, Thickness, etc.)

2. Click on any part name field to edit it.




1. Click on the Part Id field.

2. Type a number that does not conflict with the existing part IDs.



Step 27: Review the model’s data using the Solver Browser

The created solver entities are listed in the corresponding folder in Solver Browser. Eachentity has the following options: Show, Hide, Isolate and Review to help you navigatethrough the model.

1. Select dtor in the *DEFORMABLE_TO_RIGID folder.

2. Right-click and choose Isolate to show only the entities that are referred in this keyword.



3. Right click and choose Rev iew to highlight the entities.

4. Select the folder *BOUNDARY, right-click and select Show. The entities on which theloads in the folder are defined are displayed, as well as the load handles.

The exercise is complete. Save your work to an .HM file.

Exercise 2: Define Boundary Conditions and Loads forthe Seat Impact Analysis

This exercise will help you continue to become familiar with defining LS-DYNA boundaryconditions and loads using Engineering Solutions.

In this exercise, you will define boundary conditions and load data for an LS-DYNA analysis ofa vehicle seat impacting a rigid block. The seat and block model is shown in the image below.

Seat and block model

This exercise contains the following three tasks.

Define gravity acting in the negative z-direction with *LOAD_BODY_Z

Define the seat’s acceleration with *BOUNDARY_PRESCRIBED_MOTION_NODE

Export the model to an LS-DYNA 971 formatted input file and submit it to LS-DYNA

Step 1: Make sure the LS-DYNA user profile is still loaded

1. Click Preferences > User Profiles, or click the Load User Profile icon .

2. Select Engineering Solutions > C rash > LS-DYNA.




1. Retrieve the model file, seat_2.hm.

2. Take a few moments to observe the model using various visual options available (rotation,zooming, etc.).

Step 3: Define gravity acting in the negative z-direction with*LOAD_BODY_Z

1. Click BC s > G rav ity > C reate > Parts.

2. For Name:, enter gravity.

3. Click on the Z direction checkbox.

4. Click on the load curve LC ID field twice and select the curve named grav ity curve.

5. For the load curve scale factor [SF], specify 0.001.

6. Click return.

Steps 4-5: Define the acceleration for the seat

Step 4: Create a load collector for the acceleration loads to be created

1. Right click in the Model Browser and select C reate > Load C ollector.

2. For Name:, type accel.

3. For Card image:, select none.

4. Optionally, select a Color for the load collector.

5. Click create to create the load collector.

6. Click return.

Step 5: Create acceleration loads on nodes

1. Click BC s > Im posed acce leration > Node > C reate.

2. With the nodes selector active, select nodes and select by sets.

3. Select the pre-defined entity set acce l_nodes.

4. Click on C urve and select the curve acceleration curve.

This is predefined curve that defines acceleration as a function of time.

5. For magnitude, specify 0.001.



This is the scale factor the Curve Y axis values; the curve specified in the previous stepfor the acceleration loads.

6. For the direction selector, select x-axis.

This is the x-translational degree of freedom.

7. For the magnitude% =, specify 1.0E+7.

This is the scale factor for the graphical representation of the acceleration loads. It doesnot affect the actual acceleration value.

8. Click create to create the acceleration loads.

9. Click return.

Step 6: Export the model to an LS-DYNA 971 formatted input file

1. Click File > Export > Solver Deck.

2. Make sure the template field shows LS-DYNA.

3. Enter the File name: as seat_complete.key.

4. Click Export.


1. From the Start menu on your desktop, open the LS-DYNA Manager program.


3. Load the file seat_complete.key.


Step 8 (Optional): View the results in HyperView

The exercise is complete. Save your work as an .HM file.



CRASH-1200: Model Importing, Airbags, ExportingDisplayed, and Contacts using DYNA


Define *AIRBAG_WANG_NEFSKE for the airbag mesh geometry

Define an initial velocity of 3 mm/ms in the negative x-direction for the head with*INITIAL_VELOCITY_GENERATION

Define a contact between the airbag and head with*CONTACT_AUTOMATIC_SURFACE_TO_SURFACE

Define *CONTACT_AIRBAG_SINGLE_SURFACE for the airbag

Define a contact between the plate and the airbag with *CONTACT_NODES_TO_SURFACE

Import a DYNA model

Warning and Error Messages

On import of a DYNA model, any warning and error messages are written to a file named dynakey.msg or dynaseq.msg, depending on the FE input translator used. This file is createdin the same folder from which Engineering Solutions is started.

Unsupported Cards

On import, the few DYNA cards not supported by Engineering Solutions are written to the unsupp_cards panel. This panel can be accessed from the menu bar by clicking Setup >C ontrol C ards. The unsupported cards are exported with the remaining model.

Care should be taken if an unsupported card points to an entity in Engineering Solutions. Anexample of this is an unsupported material referenced by a *PART. Unsupported cards arestored as text and pointers are not considered.

LSTC Dummy Files

You can read LSTC Hybrid III dummy files into Engineering Solutions by first converting thetree file to FTSS/ARUP tree file format.

Include Files

*INCLUDE is supported. From the menu bar, click File > Im port. Use the options to merge,preserve or skip include files. When include files are read, the IDs of non-existing entitiesare maintained and these IDs are not used for new entities.

Export Displayed



From the Export tab, you can select the Displayed option to export only displayed nodesand elements. Only model data associated to the displayed nodes and elements are exported.This model data includes materials and their associated curves, properties, portions ofcontacts, and output requests.

Create and Review Contacts

The table below describes how all slave and master set types are created and specified incontacts.

Slave and master settype

DYNA card Panel used tocreate card

Equivalenttype inInterfacespanel, addsubpanel

EQ. 0: set segment id *SET_SEGMENT set_segment(contactsurfs) or …

csurfs

Interfaces, addsubpanel

entity

EQ. 1: shell element setid

*SET_SHELL_Option Entity Sets or… sets


entity

EQ. 2: part set id *SET_PART_LIST Entity Sets or… sets


comps

EQ. 3: part id *PART Collectors comps

* EQ. 4: node set id *SET_NODE_Option Entity Sets or… sets


entity

* EQ. 5: include all Interfaces, addsubpanel

all

* EQ. 6: part set id forexempted parts

*SET_PART_LIST Interfaces, addsubpanel and thencard image subpanel

sets



* For slave surface only

Add subpanel

While the Interfaces panel, add subpanel has several master and slave types - comps,sets, entity, etc. - to choose from in order to specify the DYNA master or slave set for a*CONTACT, only the valid master and slave types are selectable for the particular contactyou are creating.

When the master or slave type is set to comps and only one component is selected, theDYNA type is 3, part ID, and *PART is created. When multiple components are selected, theDYNA type is 2, part set ID, and *SET_PART_LIST is created.

When the master or slave type is set to sets, only those sets valid for the particularcontact you are creating are selectable. For example, for *CONTACT_NODES_TO_SURFACE,only a list of node sets is available for slave; you will not see a list of other set types, likeelement or part sets.

Review Contacts

You can review contacts with the review button in the Interfaces, add subpanel.

Exercise: Define Airbag, Velocity, and Contacts forthe Airbag Analysis

This exercise will help you become familiar with defining LS-DYNA airbags using EngineeringSolutions. It will also help you continue to learn how to define LS-DYNA loads and contactsusing Engineering Solutions.

In this exercise, you will define an airbag, velocity, and contacts for an LS-DYNA analysis of ahead impacting an inflating airbag. The head and airbag model is shown in the image below.

Head and airbag model




1. From the startup menu, click Engineering Solutions > C rash > HyperMesh.

2. Select LS-DYNA.

Step 2: Import the LS-DYNA model

1. From the menu bar, select File > Im port > Solver Deck.

2. In the File: field, browse to the file airbag_start.key.

3. Click Im port.

Steps 3-5: Define *AIRBAG_WANG_NEFSKE for the airbagmesh geometry

Step 3: Create a set of parts containing the AirbagFront and AirbagRearcomponents

1. Click Model > Set > Part > C reate.

2. For name =, type airbag_set.

3. For card image, select Part.

4. Click on com ps and select the components AirbagFront and AirbagRear.



Step 4: Define the airbag (*AIRBAG_WANG_NEFSKE)

1. Click Safety > Airbag > C reate.

2. For Name:, type airbag.

3. Set the card image field to airbag.

4. With the set selector active, select the entity set airbag_set.

The parts in this set define the airbag’s geometry.

5. Click create to create the card.

6. Click edit to edit card image of the control volume.

7. Enter the following data in the card image.



Field Value Parameter description

CV 1023. 0 Heat capacity at constant volume

CP 1320. 0 Heat capacity at constant pressure

T 780. 0 Temperature of input gas

LCMT cur ve i d 1 Load curve specifying input mass flow rate

C23 1. 0 Vent orifice coefficient

LCA23 cur ve i d 2 Load curve defining vent orifice area as a functionof pressure

CP23 1. 0 Orifice coefficient for leakage

PE 1. 0E- 4 Ambient pressure

RO 1. 0E- 9 Ambient density

GC 1. 0 Gravitational conversion constant

8. Click return twice to close the card image and then close the panel.

Step 5: Define an initial velocity of 3 mm/ms in the negative x-directionfor the head with *INITIAL_VELOCITY_GENERATION

1. Click BC s > Initia l Ve locity > Node set > C reate.

2. For Name:, type velocity and click C reate/edit to edit the card image.

3. Under Option, switch the toggle to G eneration.

4. Under STYP, switch the toggle to select Part ID for the set type.

5. Click the PID button twice to select the Head component.

6. For velocity in the X direction VX field, specify –3.


Steps 6-12: Define a contact between the airbag andhead

Step 6: Create a group with the card image SurfaceToSurface

The following steps explain contact creation using the menu bar.



1. Click BC s > C ontact > Surf to Surf > C reate.

2. For Name: type Airbag_Head and click C reate to create the card.

Step 7: Specify the head to be the master surface with surface type 3,part ID


2. Set the master surface type to com ps.

3. Click com ps and select the Head component.

4. Click update for the master selection.

5. Stay in the add subpanel for the next step.

Step 8: Specify all of the airbag to be the slave surface with surfacetype 2, part set ID

1. Set the slave surface type to sets.

2. Click sets and select the pre-defined entity set airbag_set.

This set contains the AirbagFront and AirbagRear components.

3. Click update in the slave line to update the slave selection.


Step 9: View the master and slave entities and set the option to automatic

1. Click rev iew.

2. Notice the master and slave entities are temporarily displayed blue and red, respectively.All other entities are temporarily displayed grey.

3. Click on the card im age subpanel and click edit.

4. Set the Option toggle to Autom atic.


Step 10: Define contact between surfaces of the airbag

The following steps explain contact creation using the Solver Browser.

1. Right click in the Solver Browser and select C reate > *C ONTAC T > C ONTAC T (A-O) >*C ONTAC T_AIRBAG _SING LE_SURFAC E.

2. For Name, type airbag and click OK to create the card.





Step 11: Define all of the airbag to be the slave surface with slave settype 2, part set ID


2. Set the slave: surface type to sets.

3. Click sets and select the pre-defined entity set airbag_set.

4. Click update to update the slave selection.


Step 12: View the slave entities

1. Click rev iew.

2. Notice the slave entities are temporarily displayed red. All other entities are temporarilydisplayed grey.


Steps 13- 16: Define a contact between the plate and theairbag with *CONTACT_NODES_TO_SURFACE

Step 13: Create *CONTACT_NODES_TO_SURFACE card

1. Click BC s > C ontact > Node to Surf > C reate.

2. For Name:, type Airbag_Plate and click C reate to create the card.

Step 14: Specify the AirbagRear_master contactsurf for the contact’smaster surface


2. Set the master surface type to csurfs.

3. Click edit to open the Contact Surface panel.

4. For name=, type AirbagRear_master.

5. For card image =, select setSegm ent.


7. With the elems selector active, click elem s >> by collector.



8. Select the AirbagRear component.


Notice the contactsurf’s pyramids point into the airbag. They should point out. In the nextstep you will reverse their direction.

10. Select the adjust norm als subpanel.

11. With the contactsurf active, select AirbagRear_m aster.

12. Toggle from by e lem s to all e lem s.

13. Click reverse norm als.

14. Click return to exit the panel and return to the Interface panel.

15. Click update to update the master selection.


Step 15: Define the plate to be the contact’s slave surface

1. Set the slave surface type to entity.

2. Click nodes and select by collector.

3. Select the RigidPlate component.

4. Click add to add the slave selection.


Step 16: View the master and slave entities

1. Click rev iew.

2. Notice the master and slave entities are temporarily displayed blue and red, respectively.All other entities are temporarily displayed grey.

3. Click return to go back to the main menu.


1. Click on Export and select the icon Export Solver Deck .

2. Set Template to Keyword971.

3. Click the Select file icon to select the path and enter the file name asairbag_complete.key.

4. Under Export options, set Export: to All.

5. Click Export.




1. From the Start menu, open the LS-DYNA Manager program.


3. Load the file airbag_complete.key.



The exercise is complete. Save your work to a .HM file.



CRASH-1300: Rigid Wall, Model Data, Constraints, andOutput using DYNA


Create *PART_INERTIA for the component vehicle mass to partially take into accountthe inertia properties and mass of the missing parts.

Create velocity on all nodes but the barrier nodes with *DEFINE_BOX and*INITIAL_VELOCITY.

Make the closest row of nodes of the crash boxes a part of the vehicle mass rigid bodywith *CONSTRAINED_EXTRA_NODES.

Create a contact between the crash boxes, the bumper and the barrier with*CONTACT_AUTOMATIC_GENERAL.

Specify the output of resultant forces for a plane on the left interior and exterior crashboxes with *DATABASE_CROSS_SECTION_PLANE.

Create a stationary rigid wall to constrain further movement of the barrier after impactwith *RIGIDWALL_PLANAR_FINITE.

Specify some nodes to be output to the ASCII NODOUT file with*DATABASE_HISTORY_NODE.

*PART_INERTIA

The INERTIA option allows inertial properties and initial conditions to be defined rather thancalculated from the finite element mesh. This applies to rigid bodies only.

When importing a DYNA model into Engineering Solutions, the *PART_INERTIA IRCS parametervalue is changed from 0 to 1. (The inertia components are changed from global to local axis.)This allows inertia components to be automatically updated when *PART_INERTIA elementsare translated or rotated. When selecting *PART_INERTIA elements to translate or rotate,select elements by comp. This selection method ensures the inertia properties areautomatically updated.

*CONSTRAINED_EXTRA_NODES

This card defines extra nodes to be part of a rigid body.

*DATABASE_CROSS_SECTION_(Option)

*DATABASE_CROSS_SECTION_(Option) defines a cross section for resultant forces written to



the ASCII SECFORC file. The options are PLANE and SET.

For the PLANE option, a cutting plane must be defined. For best results, the plane shouldcleanly pass through the middle of the elements, distributing them equally on either side.

The SET option requires the equivalent of the automatically generated input via the cuttingplane to be identified manually and defined in sets. All nodes in the cross-section and theirrelated elements contributing to the cross-sectional force resultants should be defined insets.

*DATABASE_CROSS_SECTION_SET and *DATABASE_CROSS_SECTION_PLANE are createdfrom the Solver Browser. Like the Interfaces panel, anything created from the Rigid Wallspanel is a HyperMesh group. Thus, to rename, renumber or delete a*DATABASE_CROSS_SECTION card, select groups from the Rename, Renumber or Deletepanel.

*RIGIDWALL

A *RIGIDWALL provides a method for treating contact between a rigid surface and nodalpoints of a deformable body.

Exercise: Set Up the Bumper Model for ImpactAnalysis

This exercise will help you become familiar with defining LS-DYNA rigid walls using EngineeringSolutions, Crash - LS-DYNA user profile. It will also help you continue to learn how to defineLS-DYNA model data, constraints, and output.

In this exercise, you will define model data, loads, constraints, a rigid wall, and output for anLS-DYNA analysis of a bumper in a 40 percent frontal offset crash. The bumper model isshown in the image below.

Bumper model




1. Select Engineering Solutions > C rash > HyperMesh.

2. Select LS-DYNA.

Step 2: Import the LS-DYNA model bumper_start.key

1. Click File > Im port > Solver Deck.

2. In the File: field, browse to the file bumper_start.key.

3. Click Im port.

Step 3: Define *PART_INERTIA for the vehicle mass component topartially take into account the inertia properties and mass of themissing parts

1. Right click on vehicle m ass in the Model Browser and click C ard Edit.

2. Click the switch under Options and select Inertia.

3. For the center of mass coordinates XC enter 700.

4. In the YC field, enter 0.

5. In the ZC field, enter 170.

6. For translational mass TM, specify 800.

7. For the components of the inertia tensor, specify the following:

IXX IXY IXZ IYY IYZ IZZ

1.5E+07 -5.0E+03 -8.0E+06 5.0E+07 -900 6.0E+07

8. For the initial translational velocity along the X-axis, VTX, specify -10.


Step 4: Create a box that contains all nodes but the barrier nodes

1. Click Model > Box > C reate.

2. In the name= field, type box velocity.

3. Optionally select a color.

4. Toggle lower bound from corner node to x=, y=, z=.



5. Specify the lower and upper bounds as follows:

lower bound upper bound

X= -530 200

Y= -800 800

Z= 0 300

6. Click create to create the box.


Step 5: Create initial velocity on all nodes but the barrier nodes

1. Click BC s > Initia l Ve locity > Node Set > C reate.

2. For Name, type velocity and click C reate/edit to create the card.

3. For the initial velocity in the global X direction, VX, specify –10.

4. Click on the BOXID field and select the box ve locity created in Step 4.


Note: You can also create velocity boundary condition on a set of nodes by clicking the

Load C ollectors icon in the toolbar and selecting Initialvel as the card image.

Step 6: Review the closest nodes which are in the pre-defined node setnamed Constrain Vehicle

1. In the Solver Browser, right-click on C onstra in Vehicle and select Rev iew.

Notice the set’s nodes are highlighted.

2. Right click on C onstra in Vehicle again and select Reset rev iew to return to normaldisplay mode.

Step 7: Create *CONSTRAINED_EXTRA_NODES_SET

1. Click C onnections > Extra node > C reate.

2. In the Name field, enter ExtraNodes.

3. Click C reate/edit to create the card and open the Card Image panel.

4. Click the part id (PID) field to activate it, and then select it again. Select the vehiclem ass component. This is the rigid body to which the nodes will be added. The ID isautomatically entered into the card.




Stay in the Interfaces panel for the next step.

Step 8: Define the nodes in the Constra in Vehicle set to be a part of thevehicle mass rigid body


2. Make sure name= is set to ExtraNodes.

3. Set the slave type to sets.

4. Click on sets and select the C onstra in Vehicle set.

5. Click se lect.



Note: You can also create an extra node set on a set of nodes in the Solver Browser byright clicking and selecting C reate > C onstra ined_Extra_node.

Step 9: View the extra nodes that are a part of the vehicle mass rigidbody

1. Click rev iew.

Notice the extra nodes are temporarily displayed red while the PID (vehicle mass) istemporarily displayed blue. All other entities are temporarily displayed grey.


Step 10: Create general contact

1. Click Bcs > C ontact > G enera l > C reate.

2. For name, type impact.

3. Click C reate/edit to create the card.

Note: You can also create *CONTACT_AUTOMATIC_GENERAL by right-clicking in the SolverBrowser and selecting C reate > *C ONTAC T (A-O) > Autom aticG enera l.

Step 11: Define the slave parts


2. Make sure name= is set to impact.

3. Set the slave type to sets.



4. Click on edit.

The Entity Sets panel opens, where you can create the set.

5. For nam e=, type Exempt Parts.

6. Make sure the card image field is set to Part.

7. With the comps selector active, select the vehicle m ass component.



Notice you are back in the Interface panel.


11. Select the card im age subpanel.

12. Click edit to edit the group.

13. Activate the option ExemptSlvPartSet.

14. Notice the slave surface type SSTYPE value changes from 2 (part set ID) to 6 (part setID for exempted parts). This implies all entities except the entities in the set are definedas slave for the contact.

15. For the static coefficient, FS, specify 0.15.



Step 12: Define a section by creating*DATABASE_CROSS_SECTION_PLANE

1. Click Output > Section > C reate.

2. In the Name field, type Xsection_Plane.

3. Click C reate to create the part.

4. Stay in the same panel for the next step.

Note: You can also create *DATABASE_CROSS_SECTION_PLANE from the Solver Browserby right-clicking and selecting C reate > *DATABASE_C ROSS_SEC TION_PLANE.

Step 13: Define the location and size of the section’s plane

In this subpanel, the plane’s origin (the tail of the normal vector) is defined by a base node.Create a node from the Create Nodes panel by following steps 1 - 4 below and then select itfor the base node.

1. Press the F8 key to open the Create Nodes panel.



2. Select the XYZ subpanel.

3. For x=, y= and z=, enter the values –320, -500 and 100, respectively.

4. Click create to create the node.

Notice the node is created and is displayed.

5. Click return to go back to the geom subpanel of the Rigid Walls panel.

6. With the base node selector active, graphically select the node just created.

7. Switch normal vector to x-axis.

This defines the wall’s normal vector.

8. Leave shape set to plane.

9. Toggle from infinite to finite.

10. Toggle from corners to dist/axis.

11. Switch local x axis: to y-axis.

This defines the edge vector L.

12. For len x= and len y=, specify 100 and 200, respectively.

Doing this defines the extent of the section. The values are the length of the edges a andb in the L and M directions, respectively.

13. Click update to update the group.


Step 14: Specify the parts for the selection


2. Set the slave type to com ps.

3. With the comps selector active, select the components interior crashbox and exteriorcrashbox.



Note: During export, a set is created from the selected comps and is attached to thesection definition in its card image.

Step 15: View the entities

1. Click rev iew. Notice the slave entities are displayed red while the section wall is displayedblue. All other entities are temporarily displayed grey.




Step 16: Create a box containing the nodes making up the barrier andbumper’s left side

These nodes will be slave to the rigid wall.

1. Click Model > Box > C reate.

2. In the name= field, type half model.




X= -600 -460

Y= -800 0

Z= 0 400



Step 17: Define a planar rigid wall

1. Click BC s > Rigid wall > Planar > C reate .

2. In the Name field, type wall.

3. Click C reate.

4. Stay in the Rigid Walls panel for the next step.

Note: You can also create *RIGIDWALL_PLANAR_FINITE by right-clicking in the SolverBrowser and selecting C reate > *RIG IDW ALL_PLANAR_FINITE.

Step 18: Define the location and size of the rigid wall

In this subpanel, the rigid wall’s origin (the tail of the normal vector) is defined by a basenode. Create a node from the Create Nodes panel by following steps 1-4 below and thenselect it for the base node.

1. Make sure name=, is set to wall.




3. Select the XYZ subpanel.


5. Click create. Notice the node is created and is displayed.

6. Click return to go back to the Rigid Walls panel, geom subpanel.

7. With the base node selector active, select the node that was created in step 4.

8. Switch normal vector: set to x-axis.

9. Leave shape: set to plane.

10. Toggle from infinite to finite.

11. Toggle from corners to dist/axis.

12. Select y-axis for local x axis.

13. For len x= and len y=, specify 615 and 250, respectively.

These values define the extent of the wall. They are the length of the edges l and m,respectively.


15. Stay in the Rigid Walls panel for the next step.

Step 19: Edit the card image for the rigid wall to specify the nodes inthe *DEFINE_BO X half model as slave to the rigid wall

1. Select the card subpanel.


3. Click the BOXID field twice and select the box half m odel.

4. In the field FRIC, specify 1.0 for the friction coefficient.

5. Click return to go back to the Rigid Walls panel.


Step 20: Specify some nodes to study during post-processing

1. Click Output > Node > C reate.

2. In the name field, type nodeth.

3. Set the entity selector to nodes.

4. Select a few nodes of interest from the graphics area.

5. Click create to create the output block.





1. Click File > Export > Solver Deck to open the Export tab.

2. Make sure the File Type: field is set to LS-DYNA.

3. Save the file as Bumper_complete.key.

4. Click Export.


1. From the Start menu, open the LS-DYNA Manager program.


3. Load the file bumper_complete.key.



The exercise is complete. Save your work to a .HM file.



CRASH-2000: Front Impact Bumper Model

For this tutorial it is recommended to complete the introductory tutorial Pre-Processing forPipes Impact Using RADIOSS Block - RD-3520 for basic concepts on the Engineering SolutionsRADIOSS interface.

In this tutorial you will learn how to set up a RADIOSS input deck for analysis of the impact ofa bumper against a barrier behind a rigidwall. The modeling steps that are covered are:

Associating /PART, with /MAT and /PROP

Converting node-to-node connections (/RBODY) into a mesh-less welding formulation(/INTER/TYPE2 with /SPRING) using connectors

Defining the contact for the elements in the bumper with an /INTER/TYPE7 card

Defining the interaction between bumper and barrier with an /INTER/TYPE7 card

Defining the interaction between barrier and rigid wall with the /RWALL/PLANE and /BOX cards

Specify the output of resultant forces for a plane on the left interior and exterior crashboxes with /SECT

Creating a /TH/NODE card to output time history for nodes

The units used in the model are millisecond, millimeter and kilogram (ms, mm, kg), and thetutorial is based on RADIOSS Block 100

Exercise:

The model used consists of a simplified bumper model (see image below):

Bumper model



Step 1: Load the Engineering solutions - RADIOSS (BLOCK) user profile

1. Launch Engineering Solutions > C rash (HyperMesh) from the Start menu.

2. Alternatively, you can click Preferences > User Profiles or click on the Load User

Profile icon in the toolbar .

3. Select C rash and RADIOSS and click OK.

Step 2: Load the model file

1. From the toolbar, click the Open Model icon and browse to select the bumper.hm file

from the directory <install_directory>\tutorials\es\crash. Click Open.


Step 3: Define vehicle mass component to partially take into accountthe inertia properties and mass of the missing parts of the vehicle

1. Right click in the Model Browser and select C reate > C om ponent.

2. For Name, enter Vehicle mass and click C reate.

3. Click G eom etry > C reate > Nodes > XYZ.

4. In the X field enter 700.

5. In the Y field, enter 0.

6. In the Z field, enter 170.

7. Click create to create the node.


9. Click C onnections > Rigid Body > C reate.

10. Click the selector arrow next to the nodes 2-n: button and choose sets.

11. Click the yellow nodes button next to primary node and select the node created in stepseven above.

12. Click on sets and select the C onstra in Vehicle set.

13. With all the DOF’s checked, click create to create the rigid body.

Note: A spider will be drawn connecting the created node to the edge nodes of thestructure modeled.



14. Click on the card edit icon in the toolbar, set the selector to elem s and select the rigidbody created. Click edit.

15. Fill the mass and inertia information in the card image as in the table below:

Mass J_XX J_XY J_XZ J_YY J_YZ J_ZZ

800 1.5E+07 -5.0E+03 -8.0E+06 5.0E+07 -900 6.0E+07

16. Set ICOG as 4, and ISPHER as 0.

17. Click return until you close all the open panels.

Step 4: Create a node set using a box that contains all nodes but thebarrier nodes

1. Click Model > Box > Node > C reate.

2. In the name= field, enter box velocity.


4. Toggle lower bound from corner node to x=, y=, z=.



X= -530 710



Y= -800 800

Z= 0 300



Step 5: Create initial velocity on bumper but the barrier

1. Click BC s > Initia l Ve locity > Translation.

2. In the BCs Manager, enter the name as tran_vel.

3. Set the entity selector to GRNOD (BOX).

4. Click G RNOD (BOX) and select box ve locity .

5. In the BCs Manager, enter the initial velocity components as -10, 0 and 0 for Vx, Vy

and Vz fields.

6. Click the C reate button.

7. Click C lose to close the BCs Manager tab.



Step 6: Define master surface for contact

1. Open the Solver Browser by clicking View > Solver Browser.

2. Right click in the Solver Browser and select C reate > SURF_EXT > PART.

3. For name:, type barrier_surface.



4. Click on com ps and select barrier.

5. Click se lect.

6. Click create.

7. Right click in the Solver Browser and select C reate > SURF > PART.

8. For name:, type bumper_surface.

9. Click on com ps and select bum per, exterior crashbox le ft, exterior crashbox right,interior crashbox le ft and interior crashbox right.

10. Click se lect.

11. Click create.

12. Right click in the Solver Browser and select C reate > SURF > SURF.

13. For name:, type barrier_bumper_surface.

14. Click on sets and select barrier_surface and bum per_surface.

15. Click se lect.

16. Click create .

17. Click return to close the panels.

Step 7: Create self impact contact between parts of the bumper

1. Click BC s > C ontact > G enera l > C reate.

2. For name:, type impact.

3. Click create to create the card.


5. Make sure name= is set to impact.

6. Set the slave type to comps and select bum per, interior crashbox and exteriorcrashbox.


8. Set the master type to sets and select barrier_bum per_surface.


10. Click the card edit icon .

11. Click groups and select the group im pact.


13. For the static coefficient, FRIC, specify 0.15.



14. Set Igap = 2.

15. Click return until you exit all the open panels.

Step 8: Create a system that specifies the location and the cross sectionplane normal

1. Click on the Display Num bers icon in the toolbar.

2. Click on the node selector and choose by ID .

3. For the ID’s enter 6227, 6224, 5993.

4. Check the display check box on.

5. Click On.

Note: Node numbers will appear next to the node for selection in further steps.

6. Click return.

7. Click Model > System s > Fram e_Move > C reate.

8. Select node ID 6224 for origin node.

9. Select node ID 6227 for Z axis.

10. Select node ID 5993 for YZ plane.

11. Click create to create a system.

12. Click the card edit icon on the toolbar.

13. Set the entity selector to systs.

14. Pick the system and click edit.

15. Change the option from Skew to Fram e.

16. Click return until you exit all the open panels.

Step 9: Create a set of elements that will contribute to the cross-sectional force results

1. Click Model > Sets > Shell-4 > C reate.

2. In the name= field, type XsectionPlane-elements.

3. With the elements selector active, select two rows of element on either side of thesystem as shown in figure below.





Step 10: Define a section

1. Right click in the Solver Browser and select C reate > SEC T.

2. In the Name field, type Xsection_Plane.

3. Click OK to create the card.

4. Click on the Norm al vector drop down and select system id.

5. Select the system defined in the previous step by clicking on the screen.

6. Click update to update the plane geometry.

7. Click on the add subpanel.

8. Change the slaves: entity selector to sets . Click the ye llow sets button and selectXsectionPlane-e lem ents.

9. Click update to update the SET.




Step 11: Select the section for time history output

1. Click Output > Section > C reate.

2. Enter Section_force as the name.

3. Click on groups and select Xsection_Plane.

4. Click create.

5. Click edit to go to the card image.

6. Change the option from INTER to SECTION.


Step 12: Create a node set using box containing the nodes making upthe barrier and bumper’s left side

These nodes will be slave to the rigid wall.

1. Click Model > Box > Node > C reate.

2. In the name= field, type half model.




X= -600 -460

Y= -800 0

Z= 0 400



Step 13: Define a rigid wall

1. Click BC s > Rigid W all > C reate.

2. In the name: field, type wall.

3. Click create.

Stay in the Rigid Walls panel for the next step.



Step 14: Define the location and size of the rigid wall

In this subpanel, the rigid wall’s origin (the tail of the normal vector) is defined by a basenode. Create a node from the Create Nodes panel by following steps 1-4 below and thenselect it for the base node.


2. Select the XYZ subpanel by clicking the icon .


4. Click create.

Notice the node is created and is displayed.

5. Click return to go back to the Rigid Walls panel, geom subpanel.

6. With the base node selector active, select the node that was created in step 5.

7. Switch normal vector to x-axis.

8. Leave shape: set to infinite plane.


Stay in the Rigid Walls panel for the next step.

Step 15: Edit the card image for the rigid wall to specify the nodes inthe GRNOD/BOX half model as slave to the rigid wall


2. Set the slaves: entity selector to rad_box.

3. Select the C ard page and click edit to edit the rigid wall definition.

4. In the Grnod1BOX field, specify the ID of the box half model.

5. In the field FRIC, specify 1.0 for the friction coefficient.

6. Click return to go back to the Rigid Walls panel.


Step 16. Initialize sheet metal components with stamping data

1. Click on the Results Initia lizer Icon .

2. The Create/Open Process Instance dialog opens, as shown below. In the dialog selectthe folder where you will finally export the model in the Folder field.



3. Click on C reate/Open.

4. The Process Manager is displayed in the browser tab area, and the panel opens theProcess Manager, as shown below.

5. Click on Add, followed by C om ps and select the components exterior crashbox le ft,exterior crashbox right, interior crashbox le ft, and interior crashbox right.

6. Click on the Next button.

7. Change the Blank holder force to low for all the components.

8. Click on Initia lize.

The Initialization process starts. This process takes few minutes. During this time the HMsession is unavailable for editing.

9. Select % thinning for Result Type and All for Components.

10. Click on Rev iew. The components will be contoured with thinning coming from stamping.

11. Click return to come back to the results selection.

12. Similarly repeat the same series of steps for plastic strain to review initial hardening in thecomponent.



13. Click on Next until all stages are complete in the Process Manager.

14. Click on C lose to close the Results Initializer.

Note: The results are attached to the model as include files. These include files are in thesame directory as selected in step 2.

Step 17: Create output requests and control cards

1. Click Output > Engine file.

The Radioss Engine File Tool dialog opens.

2. Enter the values as shown below:



3. Click on the ANIM tab and fill in the options as shown below:



4. Click on the DT tab and fill in the options as shown below:



5. Click Apply and then click C lose.


1. Click the Export icon .

2. For File:, click the folder icon and navigate to destination directory where you want torun.

3. Enter the name as bumper_impact and click Save.

4. Click the downward-pointing arrows next to Export options to expand the panel.

5. Click Auto export engine file to export the engine file with the model file.

6. Click on Export to export both model and engine file.



Step 19: Run the solver using RADIOSS Manager

1. Go to Start > Program s > Alta ir HyperW orks 12.0 > RADIOSS.

2. For Input file, browse to the exercise folder and select the file bumper_impact_0000.rad.

Step 21: Model setup without results initialize

1. Repeat the same process from Step 1 to step 19 except step 16.

2. Save the model as bumper_impact_noresult.

Step 22: Postprocessing in HyperGraph

1. Open HyperGraph from the Startup menu.

2. Click the file open icon and load the model bumper_impactT01 file from the folder where

the model was saved in step 18.

3. Select Section for Type, Sect. for Request and FNZ for component. Click Apply to plotthe curve.

The curve describes the force carried by the section defined in step 10 during frontalimpact.

4. Click the file open icon and load the model bumper_impact_noresultsT01 file from the

folder where the model was saved in step 18.

5. Select Section for Type, Sect. for Request and FNZ for component. Click Apply to plotthe curve.

Absorb Curve 1 is above Curve 2 indicating the higher load carrying capacity of thecomponents when stamping prestrains are included as in physical impact tests.



CRASH-2100: Simplified Car Pole Impact

The goal of this tutorial is to simulate a frontal pole test with a simplified full car.

Model Description

UNITS: Length (mm), Time (s), Mass (ton), Force (N) and Stress (MPa)

Simulation time: Engine [0 – 0.06]

An initial velocity of 15600 mm/s is applied on the car model to impact a rigid pole ofradius 250 mm.

Elasto-plastic Material /MAT/LAW2 (Windshield)

Initial Density [Rho_I] = 2.5x10-9 ton/mm3

Young's Modulus [E] E = 76000 MPa

Poisson’s Ratio [nu] = 0.3

Yield Stress (a) 0 = 192 MPa

Hardening Parameter (b) K = 200 MPa

Hardening Exponent (n) n = 0.32

Elasto-plastic Material /MAT/LAW2 (STEEL)

Initial Density [Rho_I] = 7.9x10-9 ton/mm3



Yield Stress (a) 0 = 200 MPa

Hardening Parameter (b) K = 450 MPa



Hardening Exponent (n) n = 0.5

Maximum Stress [SIG_max] max = 425 MPa

Elasto-plastic Material /MAT/LAW2 (RUBBER)

Initial Density [Rho_I] = 2x10-9 ton/mm3



Yield Stress (a)0 = 1e30 MPa

Hardening Exponent (n) n = 1

Exercise

Step 1: Load the Engineering Solutions RADIOSS user profile

1. Launch Engineering Solutions > C rash (HyperMesh) from the Start menu.

2. Alternatively, you can click Preferences > User Profiles or click on the Load User

Profile icon in the toolbar .

3. Select C rash and RADIOSS and click OK.

Step 2: Load the model file

1. From the toolbar, click the Open .hm file icon and browse to select the model filefullcar.hm.

2. Click Open.


Step 3: Create and assign the material for the windshield components

1. In the Model Browser, right-click and select C reate > Materia l.

2. In the Name field, enter windshield.



3. Set the Type field to ELASTO-PLASTIC.

4. Choose M2_PLAS_JOHNS_ZERIL for Card image.

5. Activate the checkbox Card edit material upon creation.

6. Click C reate. The Card Image panel opens.

7. Enter the values as shown in the card image below:

8. Click return.

9. Right-click on C OMP-PSHELL3 and select Edit.

The Edit component dialog opens.

10. Click on the Materia l tab.

11. Check the Assign material box.

12. In the Name field, select windshie ld.

13. Click Update to update the selected components with the created material.

14. Repeat steps 9 - 14 for component COMP-PSHELL16.

Step 4: Create and assign the material for 1D components

1. In the Model Browser select all components from COMP_PROD8 to COMP_PROD14 andchoose Edit from the context sensitive menu.

A new dialog opens.

2. Click on the Materia l tab.

3. Check the Assign material checkbox.



4. For Name, enter steel.


6. Choose M2_PLAS_JOHNS_ZERIL for card image.

7. Click C reate m ateria l. The Card Image panel opens.

8. Enter the following values:



Rho_Initial 7.900e-09

E 210000.00

nu 0.300

a 200.000

b 450.000

n 0.500

SG_max 425.000

9. Click return.

10. Click update to update the selected components with the created material.

Step 5: Assign material steel for other 2D components

1. In the Model Browser, select all components from COMP_PSHELL_1 toCOMP_PSHELL_30 except COMP_PSHELL3, COMP_PSHELL16 and COMP_PSHELL20to COMP_PSHELL23, COMP-PSOLID_24 – COMP-PSOLID_26 and choose Assign fromthe context sensitive menu.

2. For the material, select Stee l.

3. Click on assign to assign the steel material to the selected components.

Step 6: Create and assign the material for the rubber components

1. In the Model Browser select C OMP-PSHELL20 to C OMP-PSHELL23 and select Editfrom the context sensitive menu.

A new dialog opens.

2. Go to the Materials tab.

3. Check Assign material.

4. For name, enter rubber.


6. Choose M2_PLAS_JOHNS_ZERIL for the Card image field.

7. Click C reate m ateria l. The Card Image panel appears as shown in the image below.

8. Enter the values as shown in the card image below:




10. Click update to update the selected components with the created material.

Step 7: Create a Rigid Wall


2. For name, enter Ground and click C reate.

3. Go to the geom subpanel.

4. For shape, select infinite plane.

5. Click on base node and select any node from the model.

6. Click the edit button and input X = 0, Y = 0, and Z = -1.

7. Click return.

8. Toggle the switch under normal vector and select com ponents.

9. In the Z comp field, define the normal vector Z= 1.

10. Click update.

11. Go to the add subpanel. In the dist field, enter 200 for slave nodes search.

12. Click update and then click return.

Step 8: Create a Cylindrical Rigid Wall to represent pole


2. Enter RW as the name and click create.

3. Go to the geom subpanel.

4. For shape, select cy linder.

5. Click on base node and select any node from the model.

6. Click the edit button and input X = -320, Y = 1250 and Z = 0.

7. Click return.

8. In the radius = field, enter 250. In the length = field, enter 500.

9. Under normal vector, in the Z comp field, define the normal vector Z= -1.



10. Click update.

11. Go to the add subpanel. In the dist field, enter 1500 for slave nodes search.

12. Click update and then click return.

Step 9: Defining Self Contact between the parts of the vehicle

1. Click BC s > C ontact > G enera l > C reate.

2. Make sure you are in the create subpanel. For name =, enter CAR_CAR.

3. Select a color and click create.

4. Go to the add subpanel to define the master and slave.

5. For the master surface, click the switch to com ps.

6. Hide all the 1D and 3D parts in the model using Mask Browser, Model Browser propertyview, or Solver Browser and isolating PROP > SHELL.

7. Click on com ps >> displayed.

8. For slave nodes, select com ps in the drop down menu.

9. Click on com ps >> a ll in the model.

10. Click rev iew to graphically view the entities in the interface.

The master entities of the interface are drawn in blue and the slave entities in red.

11. Go to the card image subpanel and click edit.

12. Enter FRIC as 0.200 and GAPmin as 0.7.


Step 10: Defining Contact between Engine and Radiator

1. Click BC s > C ontact > G enera l > C reate .

2. Enter the name= as ENGINE_RADIATOR.

3. Optionally select a color and click create.

4. Go to the add subpanel to define the master.

5. For the master surface, click the switch to sets and click edit to go to the Entity Setspanel.

6. For name, enter engine and set the card im age to SURF_EXT.

7. Set the entity selector to comps and select com p-psolid_24 (engine).


9. Click return to go back to the Interface panel.




11. For slave, set the entity selector to comps and select comp-psolid_26 (radiator).


13. Go to the card image subpanel and click edit.

14. Input the values, as shown below.


Step 11: Defining initial velocity

1. From the Utility Menu, start the BCs Manager.

2. For Name, enter 35MPH, set the Select type field to Initia l Ve locity and set GRNOD to

Parts.

3. Click on the parts and select all in the model.

4. Set Vx as 15600.



5. Click C reate to create the boundary condition and boundary condition appears in thetable.

Step 12: Create Time History Nodes

1. Using either the Model Browser, or the Solver Browser and a virtual collector, isolatethe rail parts (PCOMP-SHELL19) in the graphics area.

2. Click Output > Node > C reate.

3. For name =, enter Rail and select nodes on the rail, as shown below.



4. Click create, followed by edit.

5. In the Var: field, enter DEF.


Step 13: Allocate Required Memory

1. From the Model menu, select C ontrol cards.

2. Click on Mem oryReq.

3. Input NMOTS as 75000.

4. Click return.

Step 14: Create output requests

1. From the Output menu, click Engine File.

The Radioss Engine File Tool dialog opens.

2. In the GENERAL tab, enter the values, as shown in the following image.



3. Click Apply.

4. In the ANIM tab, enter values as shown in the following image:



5. Click Apply and then click C lose.


1. From the toolbar, click the Export icon .

2. For File:, click the folder icon and navigate to destination directory where you want torun.

3. Enter the name as fullcar and click Save.

4. Click the arrows next to Export options to expand the panel.

5. Click Auto export engine file to export the engine file with the model file.

6. Click on Export to export both model and engine file.



Step 16: Run the solver using RADIOSS Manager

1. Click Start > Program s > Alta ir HyperW orks 12.0 > RADIOSS.

2. For Input file, browse to the exercise folder and select the file fullcar_0000.rad.





NVH

The following tutorials are available for the NVH user profile:

NVH-1000: Acoustic Cavity

NVH-1100: NVH Director Assembly

Packaged Solution Offering

Starting from 12.0, NVH Director features will be reorganized into two packages, oneincludes general NVH features which will continue to be available as a part of the standardHyperWorks, another includes high productivity NVH features which will be available throughthe Packaged Solution Offerings (PSO) NVH Director product, and will not appear in thestandard HyperWorks without a PSO license feature.

1. Standard HyperWorks Package

Meshing

o Cavity Mesher

o Coarse Mesher

o Loadcase setup process managers in generic HyperMesh mode

o All RADIOSS solver NVH functionalities

o Post-processing utilities (all but Integrated Diagnostics)

o Modal/panel participation

o Grid participation

o TPA

o DSA

o Order Analysis

2. Packaged Solution Offerings (PSO) Package

HyperMesh - NVH user profile under Engineering Solutions

o Assembly Browser

o Network View

o Analysis manager

o Job manager

o Loadcase setup process managers in NVH user profile mode

o HyperView/HyperGraph - Integrated Diagnostics utility



NVH-1000: Acoustic Cavity

Step 1: Set the User Profile to RADIOSS Bulk Data

Step 2: Open the model

1. Click File > Open > Model.

2. Browse to <installation_directory>/tutorials/es/nvh/acoustic.hm.

3. Click Open to open the model into session.

Step 3: Hide the seat cushion components

1. Expand the Components folder in the Model Browser.

2. Select Rear_Seat_C ushion, IN-driver seat back cushion, IN-crv seat head rest, IN-driver seat lower cushion, IN-pass seat lower cushion, and IN-pas seat head restfrom the list of components.



3. Right click and select H ide.

Step 4: Preview the mesh

The imported model has been restricted to just those parts that will be used to create thecavity. The seat cavities have already been built in this model.

1. Click Mesh > C reate > Acoustic C av ity Mesh to open the Acoustic Cavity MeshGeneration panel.

2. Click the com ps selector for structure to open the Component Selection panel.

3. Click com ps >> displayed to select all components.

4. Click se lect to complete the selection.

5. Click the com ps selector for seats.

6. Click the Last Page ( ) button to go to the last page of components.

7. Select the IN pass seat back cushion, IN pas seat head rest andRear_Seat_C ushion on this page.

8. Click the Prev ious Page button and select IN driver seat back cushion, IN drv seathead rest, IN driver seat lower cushion, and IN pass seat lower cushion.

9. Click se lect to complete the selection of the seats.

10. Make sure the seat coupling toggle is set to node to node remesh.

11. Enter 40 for element size=.

12. Enter 100 for gap patch size =.

13. Enter 200 for hole patch size =.

14. Click the create hole e lem ents option to activate it.

15. Click prev iew to see a preview of the mesh.



Preview of mesh

The mesh appears in the graphics area and the Acoustic Cavity tab opens in the tabarea.

Step 5: Review the mesh

1. Right click on AC _Structura l.1 in the Acoustic Cavity tab and click Isolate.



AC_Structural.1 isolated

2. Right click on the other components in the list and click Show.

3. Right click on AC _Structura l.1 and click Hide.

4. Click the m esh icon next to each of the seat cavities to see the mesh.

Seats added to the visible components



5. Select each of the seat cavity’s and right click and click Hide.

Step 6: Delete two of the patched holes

1. In the Model Browser, right click on the ^patched_holes component and click Show.

2. Zoom into the area shown in the figure.

3. If necessary, right click on AC _Structura l.4 and click Hide.

4. Click the Find icon to open the Find panel.

5. Click the find attached subpanel.

6. Change the attached to: setting to node.

7. Select the node in the center of the patch as shown in the image below.



8. Click find to find the elements attached to the node.

9. Click save found to use the found elements later.


11. Click the Delete icon to open the Delete panel.

12. Set the selector to elems if not already set.

13. Click elem s >> retrieve to select the elements saved earlier.

14. Click delete entity to delete the elements.

15. Rotate the model to the view shown below.



16. Repeat 5-15 to delete the elements on the opposite side.


Step 7: Preview the mesh

With the patched holes deleted, the acoustic cavity mesh will be previewed again.

1. Click Reject on the Acoustic Cavity tab.

2. Click the Isom etric View icon to reset the view of the model.

3. Click Mesh > C reate > Acoustic C av ity Mesh to open the panel.

4. Click the com ps selector for structure to open the Component Selection panel.

5. Click com ps >> displayed to select all components.


7. Click the com ps selector for seats.

8. Click the Last Page ( ) button to go to the last page of components.

9. Select the IN pass seat back cushion, IN pas seat head rest andRear_Seat_C ushion on this page.

10. Click the Prev ious Page button and select IN driver seat back cushion, IN drv seathead rest, IN driver seat lower cushion, and IN pass seat lower cushion.

11. Click se lect to complete the selection of the seats.

12. Enter 40 for element size=.



13. Enter 100 for gap patch size =.

14. Enter 0 for hole patch size =.

15. Click prev iew to preview the mesh.

Note that the rear door volumes are now a part of the overall volumes.

Step 8: Create the mesh

1. Select AC _Structura l.2 through AC _Structura l.10, right click and select Hide.

2. Uncheck the boxes in the Mesh column for AC_Structural 2 through AC_Structural.10.



3. Set the Mesh type option to Hexa-tetrahedra.

4. Set the Response points: to Read from file.

5. Click the … button to browse for the file.

6. Select AC OUSTIC _RESPONSE_PTS.csv and click Open.

7. Click Mesh to create the mesh.

Completed mesh

8. Click C lose to close the Acoustic Cavity tab.


Step 9: Rename the components created by the Acoustic Cavity Mesh

1. Open the Components folder in the Model Browser.

2. Right click on AC _Structura l.1 and click Renam e.

3. Name the component BODY_CAVITY and press Enter.

4. Right click on AC_Seat.1 and click Renam e.

5. Name the component DRV_SEAT and press Enter.


7. Name the component REAR_SEAT and press Enter.




9. Name the component PASS_SEAT and press Enter.

Step 10: Create material cards for the cavities

1. Right click in the Model Browser and click C reate > Materia l.

2. Set the Type field to FLUID.

3. Enter BODY_CAVITY into the Name field.

4. Select MAT10 for Card image.

5. Activate the Card edit material upon creation checkbox.

6. Deactivate the Close dialog upon creation checkbox as there are additional materials tocreate.

7. Click C reate to create the material and edit the material card.

8. Click [BULK] and [C ] in the Card Edit panel and leave the default values.


10. With the Create material dialog open, enter SEAT_CAVITY in the Name field.

11. Click C reate to create the material.

12. Click [C ] and enter 8.8e+4 for the value.

13. Click [BULK] and accept the default value.

14. Click return to complete the card edit.

15. Click C ance l to close the Create material dialog.



Step 11: Create properties for the model


2. Set the Type field to all.

3. Enter BODY_CAVITY into the Name field.

4. Select PSOLID for Card image.

5. Click the Materia l tab to assign a material to the property.

6. Click the Assign m ateria l checkbox to activate it.

7. Click BODY_C AVITY for the Name field.

8. Activate the Card edit upon material creation checkbox.

9. Deactivate the Close dialog upon creation checkbox as there are additional materials tocreate.

10. Click C reate to create the property.

11. Click FC TN to activate the option.



12. Click the FC TN field and select PFLUID.

13. Click return to exit the property card image.

14. Click the Property tab in the Create property dialog.

15. Enter SEAT_CAVITY into the Name field.

16. Click the Materia l tab to assign a material to the property.

17. Click the Assign m ateria l checkbox to activate it.

18. Click SEAT_C AVITY for the Name field.

19. Click C reate to create the material and edit the material card.

20. Click FC TN to activate the option.

21. Click the FC TN field and select PFLUID.

22. Click return to complete the card edit.

23. Click C ance l to close the Create property dialog.

Step 12: Assign the properties to the components

1. Expand the Property folder in the Model Browser.

2. Right click on the SEAT_C AVITY property and click Assign.

3. Click elem s >> by collector and select the REAR_SEAT, DRV_SEAT and PASS_SEATcomponents.


5. Click proceed to complete the assignment.

6. Right click on the BODY_C AVITY component and click Assign.

7. Click elem s >> by collector and select BODY_C AVITY.


9. Click proceed to complete the assignment.

Step 13: Renumber the nodes, elements, properties, and materials

1. Click G eom etry > Renum ber > Nodes to open the Renumber panel.

2. Click nodes >> displayed to select the displayed nodes.

3. Enter 9000000 in the start with field.

4. Click renum ber to renumber the nodes.

5. Change the selector to elems.



6. Click elem s >> displayed to select the displayed elements.

7. Click renum ber to renumber the elements.

8. Change the selector to props.

9. Click props and select BODY_CAVITY and SEAT_CAVITY.

10. Click renum ber to renumber the properties.

11. Change the selector to mats.

12. Click m ats and select BODY_C AVITY and SEAT_C AVITY.

13. Click renum ber to renumber the materials.



1. Click File > Export > Solver Deck.

2. For File Type select RADIOSS.

3. For Template select Bulk Data standard form at.

4. Browse to a location in the File field and enter acoustic.fem as a name for the model.

5. Expand the Export options.

6. For Export select Displayed from the menu.

7. Activate Write HM comments.



8. Click Export to export the model.

Step 15: Edit the .fem file

The .fem file is edited to remove the begin bulk and enddata cards that will allow it to be

added to an include card at a later date.

1. Open the file acoustic.fem using a text editor.

2. Use CTRL+F to find the begin bulk entry.



3. Delete begin bulk from the file.

4. Find the ENDDATA entry.



5. Delete the ENDDATA entry from the file.

6. Save the acoustic.fem file.

The .fem file is now ready to be added to an include. This completes the tutorial.



NVH-1100: NVH Director Assembly

Note: The Assembly Browser is part of the Packaged Solution Offerings (PSO), and willrequire a PSO license feature to activate.

Step 1: Start NVH

1. Select Engineering Solutions > NVH > RADIOSS from the User Profiles dialog.

Step 2: Define Assembly Hierarchy

1. From the View menu, select Assem bly Browser.

A file save warning message will be displayed informing you that the complete assemblydatabase can only be saved in the XML format as shown in step four of this tutorial.



2. From any view of the Assembly Browser, right-click and select C reate Module.

This opens the Module Create dialog.

3. Enter a module name in the dialogue, and then click OK. Repeat the process to create allroot level modules for the assembly. Expand the assembly by clicking on the ‘+’ box nextto Module Model.

Step 3: Load an Assembly Definition XML file

1. From any view of the Assembly Browser, right-click and select Im port XML andD isplay or Im port XML Only.

This opens the XML Import dialog.



2. After naming the module, you need to import an XML file. This should be an assembly

database file that you exported from the NVH Director. Click on the file folder icon tonavigate to a folder where the .xml file is located. Select the file and click OK to load the

file.

The assembly information will be loaded into HyperWorks.

Step 4: Save an Assembly Definition XML file

1. To save the Assembly definitions in XML files, click on the File View icon.



Note: The Preserve option saves an assembly XML file along with a set of nestedsubassembly files (similar to include files). The Merge option saves the assembly file withall subassembly files merged into it.

Subassembly files can be specified by clicking on the ‘-‘ icon in the XML file path column.Navigate to the desired folder and specify a file name. Export of subassembly files can becontrolled by checking/unchecking of the check box in the Export column.

Note: The Save XML option is enabled only in the File View to ensure that you areaware that the subassembly files are over-written.

Step 5: Define Module Representations

1. Right-click on any module and select Manage Representations. This brings up theModule Manager tab, and the Representation sub-tab is shown.

2. Select a module from the drop down menu marked Module to select a different module.To create a representation for the selected module, right-click inside the top part of the Representation tab.



3. Select Add to add a representation.



4. On the newly created representation change the module description, if desired. A defaultdescription is created, which you can edit.

5. After a representation has been added, use the Type field to select an appropriate Typeand a file to be associated with the representation, and click Apply. Two convenientoptions can be selected during this step:

A file assigned to the root representation can optionally be auto-assigned to be a Display representation (PLOTFE type) simultaneously by checking the Assign file toDisplay representation checkbox.

A representation can be auto-selected to be the Display representation by checkingthe Set as Display, load and extract TagPoints checkbox. This will be followed by thefile being imported into the 3-D graphics window and TagPoints defined in the fileextracted.

6. Aside from file based representations, a templated Lumped Parameter (LP) representationcan also be defined using the LP templates included in the NVH Director, or user createdtemplates.

7. Select one of the representations to be the active Display or Analysis representation by checking the appropriate radio buttons.

8. Repeat the process by selecting another module through the drop down box on the top



right side.

9. Once all representations are defined, click on the Assem bly Browser tab to review theassembly hierarchy with active Display and Analysis representations.

Step 6: Import Display Representations

1. From the Base View of the Assembly Browser, select the root Module Model.

2. Right-click and select Im port D isplay Rep > Recursive Modules to recursively load theactive Display models.

Module representation include files specified as the display representation are loadedhere.

Step 7: Manage TagPoints

1. To manage tagpoints, open the TagPoints tab of any module by right-clicking on themodule in the Assembly Browser and then select Manage TagPoints.



2. To add a tagpoint, right-click inside the tagpoint list box, and select Extract All to extracttagpoints from the comments added to the 10th field of the grids in the loaded Displaymodel.



Tagpoints displayed in the 3-D graphics area can be customized via the TagPoint Displaytool setting. By default, tagpoints are indicated with a grey sphere along with the label.Other options are available using the pull-down menu.

3. Repeat the extraction process to complete tagpoint definitions of all modules.



Step 8: Prepare a Module for Assembly

In the previous two steps, you have assumed that the representation file is already in an FEentity ID range that would not cause conflicts with other modules in the assembly, and allnecessary tagpoints already exist in the file as 10th field comments on the respective gridcards. However, these assumptions are not met in most practical applications. Necessarypreparation work needs to be done to get the module representation files to a state that isready for assembly. This section describes how to accomplish this task.

1. To start the process of preparing a module, right-click on the module and select PrepareModule to enter into the Prepare Module Mode.

The abbreviated Module ID Summary dialog opens.



In the Prepare Module Mode the HyperMesh database is first cleared to remove anypotentially conflicting FE entities, and then the root representation file is loaded intoHyperMesh. A module ID summary is then presented with all necessary information neededfor you to determine if the IDs need to be renumbered, and what range they should berenumbered to.

This dialog shown below comes up as a part of the Prepare Module action. It is split intotwo sections. The bottom section describes the finite element entity ID in the imported FEfile. The top section provides a way to renumber the IDs, if necessary, into a range that isnot in conflict with other modules in the assembly. The Proposed range is what thedialog has identified as one conflict free range, which can be modified based on options tothe right. Action is a user specified operation to organize IDs into the Proposed range.



Once an appropriate ID management action has been applied, NVH Director enters thePrepare Module Mode, and a Prepare Module tab opens up in the browser area withsub-tabs designed to help you perform many functions, such as:

Add spider: Help add spiders to a round hole. Select a type, dofs, pick center (RBE3only) and edge nodes, and then click C reate.

Add PLOTEL: Helps you with PLOTEL display elements.

Edit systems: Help relocate or orient the module by modifying the reference local



coordinate system. This takes you directly to the HyperMesh Systems panel to editexisting systems.

Orient and position: Help translate and rotate FE entities. Input values in theappropriate input boxes and push one of the buttons below to perform the function.

Assign damping: Help fill GE field of MAT1 cards. Enter a damping value in the inputbox and click All or Select to apply the damping values to all or selected materialcards.

In addition, a number of functionalities on the TagPoints tab of the Module Manager,such as Add, Assign and Generate PLOTEL elements, are enabled for you to manuallyadd tagpoints and assign them to grids in the module.



A tagpoint mapping tool is also available in the Prepare Module tab via the icon. Themapping tool is able to reconcile in bulk the current tagpoint definition in the assemblydatabase with what is in the root module file. You can also create new tagpoints byreading a .csv file that contains hard point coordinate and label information.



2. Once you are finished preparing the module, you can prepare another one from the Assembly Browser, or select to exit the Prepare Module Mode by clicking on the Xbutton on the Prepare Module tab.

You will be prompted with four representation file save options with information on IDrenumbering. Yes: The root representation file is to be saved, in this case, intra and interID conflict flag will be set to Yes. No: The root representation file is not to be saved, inthis case, intra and inter ID conflict flag will be set to No. Cancel: The exit PrepareModule Mode action is aborted. No, but VALIDATE: In this case there is no change tothe file and no need to save the file, but intra and inter ID conflict flag will be set to yes.

3. Once all of the modules have been prepared, you can review the assembly ID ranges andconflict setting from the Id View of the Assembly Browser.



At the individual module level, the ID tab of the Module Manager will also be populated.

Step 9: Define Connections Between Modules

1. From the NVHConnection toolbar, click on the icon to launch the connectionInteractive Create panel.



2. Connections can be created between modules to be connected either by selectingtagpoints from the list box in the panel, or by picking tagpoints. Hint: Pick and drag on theleft hand side of the tags to ease selection off the screen after clicking on the Select

TagPoints icon .

You can also provide a description for the connector created, specify an owning module, alocal coordinate system, connector location for the center of motion, and a collector forthe connector created.

3. Connections can also be created using the Auto Create panel, which can be invoked by

clicking on the icon. Two automated creation approaches are available: auto creationby Proximity or by Tagpoint Matching.

4. To review the connections that were created, select C onnector Browser from the Viewmenu.



The Connector Browser is divided into two browser panes. The top pane is the ModulePane, where connected modules are listed. You can view connections attaching tomodules using typical browser functions, such as Show/Hide/Isolate.

The lower pane is the Connector Pane, where individual connections are listed.



Three connection views are available from the Connector Pane.

Connectivity View : Columns in this view focus on connectivity related details. Ofparticular importance are the following columns:

PointA/PointB: These two columns show the two tagpoints on two modules that arebeing connected for each connection. The same order (PointA first and PointB second)is used when generating connection FE entities during connector realization. PointA/PointB may be shown with two incomplete status indications (in square brackets): [N/A] indicates that the tagpoint exists in the assembly database, but is not available inthe HyperMesh session (not imported.) [Undefined] indicates that the tagpoint doesnot exist in the current assembly database, which means the tagpoint is either deletedor the sub .xml file it travels with is not imported in the session.

Owning module: This column indicates which module owns the particular connection.The owning module is always the module on the PointA side of the connection. Theconnection definition and properties always travel with or organized under their owningmodules when sub .xml files are written.

Distance: This column shows the distance between PointA and PointB. It can be used



as a metric for checking the validity of the connection. Connections spanning largedistances are potentially connected by mistake. Some NVH engineers prefer to keep allconnections at zero length due to fear that non-zero length springs may introduceunintended dynamic motion, which is a valid concern if celas type spring elements areused during connector realization. When cbush type spring and rbe2 type rigidelements are used, this is the case for all current NVH Director supported realizationtypes, correct dynamic motion is ensured by element formulation, and there is nolonger a need to maintain zero connection length.

Switch nodes: This column shows if there is a need to switch the order by whichPointA and PointB are used in generating rbe2 rigid elements during connectorrealization. This need is driven solely by dependency considerations of the connectedpoints, since a point that is already dependent cannot be made the dependent pointagain in the connection element definition. Four possible states of this column arepossible. No: If PointA is independent, regardless of the dependency of PointB. Yes: IfPointA is dependent, but PointB is independent, in which case PointB will be made theindependent point in realizations involving rbe2. Unresolvable: This happens whenboth PointA and PointB are already dependent, in which case a realization involving rbe2 is not possible, and the connection will fail to realize. Unknown: If PointA’sdependency status is unknown or if PointA is dependent and PointB’s dependencystatus is unknown.

Property View : Columns in this view focus on connection property types defined,local coordinate systems used and property set that is active.

Location View : Columns in this view focus on the location definition.

5. To review unattached modules, go to the Assembly Browser and select FindUnattached Modules. This action removes all modules attached by connections andprovides a good way check if all components shown in the 3-D graphics window areintentionally unattached.

6. Similarly, select Find Unattached TagPoints to see if some TagPoints are unattached byaccident.

Step 10: Define Connection Information and Properties

1. Connection properties can be defined by first selecting a connector, right-click, andselect Manage C onnection.



This opens the General tab of the Connection Manager, where you can edit theconnector’s general information including Label, Description and Owning Module.

2. Click on the Update button to save the changes.

A connection location type can be defined by selecting one of the options from the pull-down menu: Point A, Point B, Midpoint, or a CustomLocation. When CustomLocationis selected, the location can be defined either by specifying a specific coordinate, or bymapping it to a Hardpoint location.



3. Click on the Update button to save the changes.

Information related to Connected Points, and distance between them, is displayed in the

next section. You can modify any connecting tagpoint by clicking on the icon next toits label, which brings up the Tagpoint Selection tool. You can then select a module first

in the Module pull-down list, select a tagpoint owned by the module, or click on the



icon and pick a tagpoing on the screen in the 3D graphics window, and then click Select.

The tagpoint list can be further filtered by clicking on the icon and selecting one ofthe tagpoint types: Response, Connection, Input, Plot, or All (default).

When checked, the Switch Nodes check box allows you to change the independent nodefrom Point A to Point B, based on their dependency status, to avoid an alreadydependent node being specified as dependent again when the connection is realized intonew rigid elements. Connection properties are defined in the States tab of theConnection Manager.



The first step in defining connection properties is to select a State Set. State Set isdesigned to capture a unique hardware part with its own set of connection properties. Forexample, hydromount vs. a base rubber part. By default, a base State Set is alreadycreated and assigned to the connector. Therefore, unless there is a need for multiple setsof properties, the default base State Set selection does not need to be changed.

4. To select another State Set click on the Edit... button. This opens the Select State Setdialog.



State Sets can be added by clicking on the icon, or deleted by clicking on the icon. You can double click on a State Set to edit its name, and click on the Select buttonto finalize the selection.

The second step in defining connection properties is to select a LCS (local coordinatesystem) for the properties to be defined in the next step.

As seen in the screenshot above, four options are available in specifying coordinatesystems used by any element generated during connection realization:

Vehicle – ‘0’ or the basic coordinate system is used.

Owned – This option allows you to create a custom LCS by clicking on the Edit…button.

TagPointA – Local coordinate system specified as the output Displacement CoordinateSystem on the grid card associated when TagPointA is used.

TagPointB – Local coordinate system specified as the output Displacement CoordinateSystem on the grid card associated when TagPointB is used.

When the Owned local coordinate system is selected, a local coordinate system managed



in the assembly can be created using the Define Local Coordinate System dialog. Threetypes of coordinate systems can be defined:

Axis-Plane – Two vectors are required to define this system. A vector can either bespecified in direction cosines, or by selecting two tagpoints.

Angle – Any combinations of angle rotations around the reference axes can be usedto define this system.

Ujoint – The Ujoint coordinate systems is defined by selecting two tagpoints on theinput shaft and two tagpoints on the output shaft. A homo-kenetic coordinate systemwill then be created to properly describe motion transfer of Ujoints from the input tothe output shafts.

The last step in defining connection properties is to define property states.

As seen in the screenshot above, five options are available in specifying property states:



PBUSH – A CBUSH element is generated during connection realization. The PBUSHcard allows you to specify K (stiffness), B (viscous damping), GE (material damping),M (mass and moment of Inertia), and RIGID (check boxes for rigidly connected dofs.)Note: The M and RIGID fields are not supported in the Nastran profile, and areignored.

RIGID – A RBE2 element with dofs specified in checked boxes is generated duringconnection realization.

PBUSHT – A CBUSH element is generated during connection realization. In addition tothe PBUSH card that specifies the base properties, a PBUSHT card allows you tospecify frequency tables for K, B, and GE.

PBUSH-MASS – A CBUSH element with two COMN2 elements at its Point A and Point Bare generated during connection realization. Note: This type is designed to be used inthe Nastran profile where the M fields for PBUSH are not supported by the Nastransolver.

PBUSH-RIGID – A CBUSH element with a parallel RBE2 element are generated duringconnection realization. Note: This type is designed to be used in the Nastran profilewhere the RIGID check boxes for PBUSH are not supported by the Nastran solver.

5. Click Apply to save each property state definition.

Property states can also be imported using the Import From File option by clicking on

the icon. This opens the Import States dialog.

6. Browse and select a connection property template file, select a connection property set,and click on Im port to load the property states.



7. Repeat the above process for all connections to complete property definition.

Step 11: Manage Analysis

An Analysis is a collection of module and connection selection that completely specifies theassembly definition for a particular simulation event. The Analysis Manager is invoked from

the Connector Browser by clicking on the icon.

1. To add an analysis by extracting active module and connection settings, click on the icon. To add an analysis by copying module and connection settings from the selected



analysis, click on the icon. To add a blank analysis, click on the icon.

2. To delete an analysis, first check the radio button corresponding to the analysis and then

click on the icon next to the name of the analysis.

The top section of the Analysis Manager is used to define analyses, which is furtherdivided into three parts. The first is for module representation and state selection, thesecond is for connection state selection, and the third is for template loadcase definition.

3. To define module representations, select the representation via the list individually, orglobally all representations by type via the right-click context menu, shown below.

4. To define connection state, pick a State label, such as idle or WOT.

5. To define template loadcase, click on the ‘…’ icon to invoke the Select LoadcaseDefinition dialog.

6. Highlight an existing definition or add a new one by clicking on the icon to open theNVH Loadcase Templates dialog.



The lower section of the Analysis Manager is used to apply the module representationand state selections to the modules in the assembly, realize connections to states definedinto corresponding FE entites and render the defined loadcase into solver cards. Once ananalysis has been applied, the Job options section is enabled.

7. If the Create job option is selected, you can select a Job folder and click the C reateJob button, which opens the Job Submission dialog, allowing you to select a number ofsolver related options. Clicking the Subm it Job button will create the analysis job andsubmit it to the target solver for analysis. Subsequently, the job will be accessible throughthe Job Manager.

8. If the Export deck option is selected, click on Export to save a solver deck for manualsubmission to the targeted solver for analysis.

All analysis information is saved in the assembly XML file, and retrieved when the file isloaded back.

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