ANSYS Mechanical Tutorials

ANSYS Mechanical Tutorials

Release 16.0ANSYS, Inc.January 2015Southpointe

2600 ANSYS DriveCanonsburg, PA 15317 ANSYS, Inc. is

certified to ISO9001:2008.

[email protected]://www.ansys.com(T) 724-746-3304(F) 724-514-9494

Copyright and Trademark Information

2014-2015 SAS IP, Inc. All rights reserved. Unauthorized use, distribution or duplication is prohibited.

ANSYS, ANSYS Workbench, Ansoft, AUTODYN, EKM, Engineering Knowledge Manager, CFX, FLUENT, HFSS, AIMand any and all ANSYS, Inc. brand, product, service and feature names, logos and slogans are registered trademarksor trademarks of ANSYS, Inc. or its subsidiaries in the United States or other countries. ICEM CFD is a trademarkused by ANSYS, Inc. under license. CFX is a trademark of Sony Corporation in Japan. All other brand, product,service and feature names or trademarks are the property of their respective owners.

Disclaimer Notice

THIS ANSYS SOFTWARE PRODUCT AND PROGRAM DOCUMENTATION INCLUDE TRADE SECRETS AND ARE CONFID-ENTIAL AND PROPRIETARY PRODUCTS OF ANSYS, INC., ITS SUBSIDIARIES, OR LICENSORS. The software productsand documentation are furnished by ANSYS, Inc., its subsidiaries, or affiliates under a software license agreementthat contains provisions concerning non-disclosure, copying, length and nature of use, compliance with exportinglaws, warranties, disclaimers, limitations of liability, and remedies, and other provisions. The software productsand documentation may be used, disclosed, transferred, or copied only in accordance with the terms and conditionsof that software license agreement.

ANSYS, Inc. is certified to ISO 9001:2008.

U.S. Government Rights

For U.S. Government users, except as specifically granted by the ANSYS, Inc. software license agreement, the use,duplication, or disclosure by the United States Government is subject to restrictions stated in the ANSYS, Inc.software license agreement and FAR 12.212 (for non-DOD licenses).

Third-Party Software

See the legal information in the product help files for the complete Legal Notice for ANSYS proprietary softwareand third-party software. If you are unable to access the Legal Notice, please contact ANSYS, Inc.

Published in the U.S.A.

Table of Contents

Tutorials ... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . vActuator Mechanism using Rigid Body Dynamics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1Nonlinear Static Structural Analysis of a Rubber Boot Seal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11Cyclic Symmetry Analysis of a Rotor - Brake Assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35Steady-State and Transient Thermal Analysis of a Circuit Board . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51Delamination Analysis using Contact Based Debonding Capability . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61Interface Delamination Analysis of Double Cantilever Beam . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 77Fracture Analysis of a 2D Cracked Specimen using Pre-Meshed Crack . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 97Fracture Analysis of a Double Cantilever Beam (DCB) using Pre-Meshed Crack . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 107Fracture Analysis of an X-Joint Problem with Surface Flaw using Internally Generated Crack Mesh . . . . 113Using Finite Element Access to Resolve Overconstraint . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 121Simple Pendulum using Rigid Dynamics and Nonlinear Bushing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 153Track Roller Mechanism using Point on Curve Joints and Rigid Body Dynamics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 159Index .... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 167

iiiRelease 16.0 - SAS IP, Inc. All rights reserved. - Contains proprietary and confidential information

of ANSYS, Inc. and its subsidiaries and affiliates.

TutorialsThis section includes step-by-step tutorials that represent some of the basic analyses you can performin the Mechanical Application. The tutorials are designed to be self-paced and each have associatedgeometry input files. You will need to download all of these input files before starting any of the tutorials.

vRelease 16.0 - SAS IP, Inc. All rights reserved. - Contains proprietary and confidential information


Actuator Mechanism using Rigid Body Dynamics

This example problem demonstrates the use of a Rigid Dynamic analysis to examine the kinematicbehavior of an actuator after moment force is applied to the flywheel.

Features Demonstrated

Joints

Joint loads

Springs

Coordinate system definition

Body view

Joint probes

Setting Up the Analysis System

1. Create the analysis system.

Start by creating a Rigid Dynamics analysis system and importing geometry.

a. Start ANSYS Workbench.

b. In the Workbench Project page, drag a Rigid Dynamics system from the Toolbox into the ProjectSchematic.

c. Right-click the Geometry cell of the Rigid Dynamics system, and select Import Geometry>Browse.

d. Browse to open the Actuator.agdb file. A check mark appears next to the Geometry cell in theProject Schematic when the geometry is loaded. This file is available on the ANSYS Customer Portal;go to http://support.ansys.com/training.

2. Continue preparing the analysis in the Mechanical Application.

a. In the Rigid Dynamics system schematic, right-click the Model cell, and select Edit. The MechanicalApplication opens and displays the model.

1Release 16.0 - SAS IP, Inc. All rights reserved. - Contains proprietary and confidential information

http://support.ansys.com/training

The actuator mechanism model consists of four parts: (from left to right) the drive, link, actuator,and guide.

b. From the Menu bar , select Units>Metric (mm, kg, N, s, mV, mA).

Note

Stiffness behavior for all geometries are rigid by default.

3. Remove surface-to-surface contact.

Rigid dynamic models use joints to describe the relationships between parts in an assembly. Assuch, the surface-to-surface contacts that were transferred from the geometry model are not neededin this case. To remove surface-to-surface contact:

a. Expand the Connections branch in the Outline, then expand the Contacts branch. Highlight all of thecontact regions in the Contacts branch.

b. Right-click the highlighted contact regions, then select Delete.

Note that this step is not needed if your Mechanical options are configured so that automaticcontact detection is not performed upon attachment.

4. Define joints.

Joints will be defined in the model from left to right as shown below, using Body-Ground andBody-Body joints as needed to solve the model.

Release 16.0 - SAS IP, Inc. All rights reserved. - Contains proprietary and confidential informationof ANSYS, Inc. and its subsidiaries and affiliates.2


Prior to defining joints, it is useful to select the Body Views button in the Connections toolbar. TheBody Views button splits the graphics window into three sections: the main window, the referencebody window, and the mobile body window. Each window can be manipulated independently. Thismakes it easier to select desired regions on the model when scoping joints.

To define joints:

a. Select the drive pin face and link center hole face as shown below, then select Body-Body>Revolutein the Connections toolbar.



b. Select the drive center hole face as shown below, then select Body-Ground>Revolute in the Connec-tions toolbar.

c. Select the link face and actuator center hole face as shown below, then select Body-Body>Revolutein the Connections toolbar.

d. Select the actuator face and the guide face as shown below, then select Body-Body>Translational inthe Connections toolbar.



e. Select the guide top face as shown below, then select Body-Ground>Fixed in the Connections toolbar.

5. Define joint coordinate systems.

The coordinate systems for each new joint must be properly defined to ensure correct joint motion.Realign each joint coordinate system so that they match the corresponding systems pictured in step4. To specify a joint coordinate system:

a. In the Outline, highlight a joint in the Joints branch.



b. In the joint Details view, click the Coordinate System field. The coordinate field becomes active.

c. Click the axis you want to change (i.e., X, Y, or Z). All 6 directions become visible as shown below.

d. Click the desired new axis to realign the joint coordinate system.

e. Select Apply in the Details view once the desired alignment is achieved.

6. Define a local coordinate system.

A local coordinate system must be created that will be used to define a spring that will be addedto the actuator.

a. Right-click the Coordinate Systems branch in the Outline, then select Insert>Coordinate System.

b. Right-click the new coordinate system, then select Rename. Enter Spring_fix as the name.

c. In the Spring_fix Details view, define the Origin fields using the values shown below:



7. Add a spring to the actuator.

a. Select the bottom face of the actuator as shown below, then select Body-Ground>Spring in theConnections toolbar.

b. In the Reference section of the spring Details view, set the Coordinate System to Spring_fix.

c. In the Definition section of the spring Details view, specify:

Longitudinal Stiffness = 0.005 N/mmLongitudinal Damping = 0.01 N*s/mm



8. Define analysis settings.

To define the length of the analysis:

a. Select the Analysis Settings branch in the Outline.

b. In the Analysis Settings Details view, specify Step End Time = 60. s

9. Define a joint load.

A joint load must be defined to apply a kinematic driving condition to the joint object. To define ajoint load:

a. Right-click the Transient branch in the Outline, then select Insert>Joint Load.

b. In the Joint Load Details view, specify:

Joint = Revolute - Ground To DriveType = MomentMagnitude = Tabular (Time)

Graph and Tabular Data windows will appear.

c. In the Tabular Data window, specify that Moment = 5000 at Time = 60, as shown below.

10. Prepare the solution



a. Select Solution in the Outline, then select Deformation>Total in the Solution toolbar.

b. In the Outline, click and drag the link to actuator revolute joint to the Solution branch. Joint Probewill appear under the Solution branch.

This is a shortcut for creating a joint probe that is already scoped to the joint in question. Becausewe want to find the forces acting on this joint, the default settings in the details of the jointprobe are used.

c. Click the Solve button in the main toolbar.

11. Analyze the results

a. After the solution is complete, select Total Deformation under the Solution branch in the Outline. Atimeline animation of max/min deformation vs. time appears in the Graph window.

b. In the Graph window, select the Distributed animation type button, and specify 100 frames and 4seconds, as shown below. (These values have been chosen for efficiency purposes, but they can beadjusted to user preference.)

c. Click the Play button to view the animation.

d. Select the Joint Probe branch in the Outline,

e. In the Joint Probe Details view, specify X Axis in the Result Selection field.

f. Right-click the Joint Probe branch, then select Evaluate All Results.

The results from the analysis show that the spring-based actuator is adding energy in to the systemthat is reducing the cycle time.

End of tutorial.



Nonlinear Static Structural Analysis of a Rubber Boot Seal

Problem Description

This is the same problem demonstrated in the Mechanical APDL Technology Demonstration Guide. SeeChapter 29: Nonlinear Analysis of a Rubber Boot Seal. The following example is provided only todemonstrate the steps to setup and analyze the same model using Mechanical.

This rubber boot seal example demonstrates geometric nonlinearities (large strain and large deformation),nonlinear material behavior (rubber), and changing status nonlinearities (contact). The objective of thisexample is to show the advantages of the surface-projection-based contact method and to determinethe displacement behavior of the rubber boot seal, stress results.

A rubber boot seal with half symmetry is considered for this analysis. There are three contact pairsdefined; one is rigid-flexible contact between the rubber boot and cylindrical shaft, and the remainingtwo are self contact pairs on the inside and outside surfaces of the boot.


Hyperelastic Material Creation

Remote Point

Named Selection

Manual Contact Generation

Large Deflection

Multiple Load Steps



Nodal Contacts

Setting Up the Analysis System

1. Create a Static Structural analysis system.


b. On the Workbench Project page, drag a Static Structural system from the Toolbox to the ProjectSchematic.

2. Create Materials.

For this tutorial, we are going to create a material to use during the analysis.

a. In the Static Structural schematic, right-click the Engineering Data cell and choose Edit. The EngineeringData tab opens. Structural Steel is the default material.

b. From the Engineering Data tab, place your cursor in the Click here to add new material field and thenenter "Rubber Material".



c. Expand the Hyperelastic Toolbox menu:

i. Select the Neo-Hookean option, right-click, and select Include Property.



ii. Enter 1.5 for the Initial Shear Modulus () Value and then select MPa for the Unit.

iii. Enter .026 for the Incompressibility Parameter D1 Value and then select MPa^-1 for the Unit.

d. Click the Return to Project toolbar button to return to the Project Schematic.

3. Attach Geometry.

a. In the Static Structural schematic, right-click the Geometry cell and choose Import Geometry>Browse.



b. Browse to the proper folder location and open the file BootSeal_Cylinder.agdb. This file is availableon the ANSYS Customer Portal; go to http://support.ansys.com/training.

Define the Model

The steps to define the model in preparation for analysis are described below. You may wish to referto the Modeling section of Chapter 29: Nonlinear Analysis of a Rubber Boot Seal in the MechanicalAPDL Technology Demonstration Guide to see the steps taken in the Mechanical APDL Application.

1. Launch Mechanical by right-clicking the Model cell and then choosing Edit. (Tip: You can also double-click the Model cell to launch Mechanical).

2. Define Unit System: from the Menu bar , select Units> Metric (mm, kg, N, s, mV, mA). Also select Radiansas the angular unit.

3. Define stiffness behavior and thickness: expand the Geometry folder and select the Surface Body object.Set the Stiffness Behavior to Rigid and enter a Thickness value of 0.01 mm.



4. In the Geometry folder, select the Solid geometry object. In the Details under the Material category, openthe Assignment property drop-down list and select Rubber Material.

5. Create a Cylindrical Coordinate System: Right-click the Coordinate Systems folder and select Insert>Co-ordinate System. Highlight the new Coordinate System object, right-click, and rename it to "CylindricalCoordinate System".

Specify properties of the Cylindrical Coordinate System:

a. Under the Details view Definition category, change Type to Cylindrical and Coordinate System toManual.

b. Under the Origin group, change the Define By property to Global Coordinates.



c. Under Principal Axis select Z as the Axis value and set the Define By property to Global Y Axis.

d. Under Orientation About Principal Axis, select X as the Axis value and select Global Z Axis for theDefine By property.

6. Insert Remote Point: Right-click on the Model object and select Insert>Remote Point.

7. In Details view, scope the Geometry to cylinders exterior surface, set X Coordinate, Y Coordinate, andZ Coordinate to 0, and specify the Behavior as Rigid.



8. Define Named Selections:

a. Right-click on the Model object and select Insert>Named Selection.

b. Select the exterior surface of the cylinder, Apply it as the Geometry, right-click, and Rename it toCylinder_Outer_Surface.

c. Right-click on the Surface Body object under the Geometry folder and select Hide Body. This stepeases the selection of the boots inner surfaces.



d. Highlight the Named Selection object and select Insert>Named Selection.

e. Select all of the inner faces of the boot seal as illustrated below and scope the faces as the Geometryselection. Make sure that the Geometry property indicates that 24 Faces are selected.

Press the Ctrl key to select multiple surfaces individually or you can hold down the mouse buttonand methodically drag the cursor across all of the interior surfaces. Note that the status bar atthe bottom of the graphics window displays the number of selected surfaces (highlighted ingreen in the following image).

f. Right-click the new Selection object and Rename it to Boot_Seal_Inner_Surfaces.



g. Again highlight the Named Selection object and select Insert>Named Selection.

h. Reorient your model and select all of the outer faces of the boot seal as illustrated below and scopethe faces as the Geometry selection. Make sure that the Geometry property indicates that 27 Facesare selected.

The selection process is the same. Press the Ctrl key to select multiple surfaces individually oryou can hold down the mouse button and methodically drag the cursor across all of the surfaces(except the top surface of the boot).



i. Right-click the new Selection object and Rename it to Boot_Seal_Outer_Surfaces.

9. Insert a Connection Group and Manual Contacts:

a. Highlight the Connections folder, right-click, and select Insert>Connections Group.



b. Right-click on the Connections Group and select Insert>Manual Contact Region. Notice that Connec-tion Group is automatically renamed to Contacts and that the new contact region requires definition.

c. Create a Rigid-Flexible contact between the rubber boot and cylindrical shaft by defining the followingDetails view properties of the newly added Bonded-No Selection To No Selection.

Scoping Method set to Named Selections.

Contact set to Boot_Seal_Inner_Surfaces from drop-down list of Named Selections.

Target set to Cylinder_Outer_Surface from drop-down list of Named Selections.

Target Shell Face set to Top.

Type set to Frictional.

Frictional Coefficient Value equal to 0.2.

Set Behavior set to Asymmetric.

Detection Method set to On Gauss Point.



Interface Treatment set to Add Offset, Ramped Effects.



Note

The name of the contact, Bonded-No Selection To No Selection, is automaticallyrenamed to Frictional - Boot_Seal_Inner_Surfaces To Cylinder_Outer_Surface.



d. Right-click the Contacts folder object and select Insert>Manual Contact Region. Set Contact at innersurface of the boot seal. In details view of the newly added Bonded-No Selection To No Selection,change the following properties:

Scope set to Named Selection.

Contact and Target set to Boot_Seal_Inner_Surfaces.


Frictional Coefficient value equal to 0.2.

Detection Method set to Nodal-Projected Normal From Contact.

Note

The Bonded-No Selection To No Selection is automatically renamed to Frictional- Boot_Seal_Inner_Surfaces To Boot_Seal_Inner_Surfaces.

e. Right-click the Contacts folder object and select Insert>Manual Contact Region. Set Contact at innersurface of the boot seal. Self Contact at outer surface of the boot seal. In details view of the newly addedBonded-No Selection To No Selection, specify the following properties:

Scoping Method set to Named Selection.

Contact and Target set to Boot_Seal_Outer_Surfaces.




Frictional Coefficient Value equal to 0.2.

Detection Method set to Nodal-Projected Normal From Contact.

Note

Bonded-No Selection To No Selection is automatically renamed to Frictional -Boot_Seal_Outer_Surfaces To Boot_Seal_Outer_Surfaces.

Analysis Settings

The problem is solved in three load steps, which include:

Initial interference between the cylinder and boot.

Vertical displacement of the cylinder (axial compression in the rubber boot).

Rotation of the cylinder (bending of the rubber boot).

Load steps are specified through the properties of the Analysis Settings object.

1. Highlight the Analysis Settings object.

2. Define the following properties:

Number of Steps equals 3.

Auto Time Stepping set to On (from Program Controlled).

Define By set to Substeps.



Initial Substeps and Minimum Substeps set to 5.

Maximum Substeps set to 1000.

Large Deflection set to On.

3. For the second load step, define the properties as follows:

Current Step Number to 2.




4. For the third load step, define the properties as follows:

Current Step Number to 3.






Boundary Conditions

The model is constrained at the symmetry plane by restricting the out-of-plane rotation (in CylindricalCoordinate System). The bottom portion of the rubber boot is restricted in axial (Y axis) and radial dir-ections (in Cylindrical Coordinate System).

1. Highlight the Static Structural (A5) object and:

select the two faces (press the Ctrl key and then select each face) of the rubber boot seal as illustratedhere.

right-click and select Insert>Displacement.

2. Set the Coordinate System property to Cylindrical Coordinate System and the Y Component propertyto 0.



3. Highlight the Static Structural (A5) object and select the face illustrated here. Insert another Displacementand set the Y Component to 0 (Coordinate System should equal Global Coordinate System).

4. Insert another Displacement scoped as illustrated here and set the Coordinate System property to Cyl-indrical Coordinate System and the X Component property to 0.



5. Insert a Remote Displacement from the Support drop-down menu on the Environment toolbar.

6. Specify Remote Point as the Scoping Method.

7. Select the Remote Point created earlier (only option) for the Remote Points property.

8. Change the X Component, Y Component, Z Component, Rotation X, Rotation Y, and Rotation Z prop-erties to Tabular (Time) as illustrated below.

9. In the Tabular Data specify:

Y value for Step 2 and Step 3 as -10 mm.



RZ value for Step 3 as 0.55 [rad].

Results and Solution

1. Highlight the Solution and then select Deformation>Total Deformation from the Solution toolbar.

2. Specify the Geometry as the boot body only, and set the Definition category property By as Time and theDisplay Time property as Last.

3. Highlight the Solution and then select Stress>Equivalent (von-Mises) from the Solution toolbar.

4. Specify the Geometry as the boot body only, and set the Definition category property By as Time andthe Display Time property as Last.



5. Highlight the Solution and then select Strain>Equivalent (von-Mises) from the Solution toolbar.

6. Specify the Geometry as the boot body only, and set the Definition category property By as Time andthe Display Time property as Last.

7. Click the Solve button.

Note

The default mesh settings mesh keep mid-side nodes in elements creating SOLID186 elements(See Solution Information). You can drop mid-side nodes in Mesh Details view under the Advancedgroup. This allows you to mesh and solve faster with lower order elements.

Although very close, the mesh generated in this example may be slightly different than the onegenerated in the Chapter 29: Nonlinear Analysis of a Rubber Boot Seal in the Mechanical APDLTechnology Demonstration Guide.

Review Results

The solution objects should appear as illustrated below. You can ignore any warning messages.

For a more detailed examination and explanation of the results, see the Results and Discussion sectionof Chapter 29: Nonlinear Analysis of a Rubber Boot Seal in the Mechanical APDL Technology DemonstrationGuide.

Total Deformation at Maximum Shaft Angle



Equivalent Elastic Strain at Maximum Shaft Angle (at the end of 3 seconds)

Equivalent Stress (Von-Mises Stress) at Maximum Shaft Angle



End of tutorial.



Cyclic Symmetry Analysis of a Rotor - Brake Assembly

Program Description

This tutorial demonstrates the use of cyclic symmetry analysis features in the Mechanical Applicationto study a sector model consisting of a rotor and brake assembly in frictional contact. With increasedloading of the brake, the contact status between the pad and the rotor changes from near, to sliding,to sticking. Each of these contact states affects the natural frequencies and resulting mode shapes ofthe assembly. Three pre-stress modal analyses are used to verify this phenomenon.


Cyclic Regions

Named Selections based on Criteria

Thermal Steady-State Analysis with Cyclic Symmetry

Static Structural Analysis with Cyclic Symmetry

Modal Analysis with Cyclic Symmetry

Generation of Restart Points



Modal Analysis with Nonlinear Prestress (Linear Perturbation)

Note

The procedural steps in this tutorial assume that you are familiar with basic navigationtechniques within the Mechanical application. If you are new to using the application, considerrunning the tutorial: Steady-State and Transient Thermal Analysis of a Circuit Board beforeattempting to run this tutorial.

Analysis System Layout

We will tour the different analysis systems that can leverage cyclic symmetry functionality. These comprisethermal, static structural and modal analyses:

A steady-state thermal analysis will be used to calculate the temperature distribution for the evaluation ofany temperature-dependent material properties or thermal expansions in subsequent analyses.

A nonlinear static structural analysis is configured to represent the mechanical loading of the brake ontothe rotor. Nonlinearities from large deformation and changes in contact status are included.

Modal analyses, each at different stages of frictional contact status, are established to compare the free vi-bration responses of the model.

1. Create the analysis systems.

You need to establish a static structural analysis that is linked to a steady-state thermal analysis,then establish three modal analyses that are linked to the static structural analysis.


b. From the Toolbox, drag a Steady-State Thermal system onto the Project Schematic.

c. From the Toolbox, drag and drop a Static Structural system onto the Steady-State Thermal systemsuch that cells 2, 3, 4, and 6 are highlighted in red.

d. The systems are displayed as follows:



e. To measure the free vibration response, go to the Toolbox, drag and drop a Modal system onto theStatic Structural system such that cells 2, 3, 4, and 6 are highlighted in red.

f. Repeat step e two more times to complete adding the remaining analysis systems. The layout of theanalysis systems and interconnections in the Project Schematic should appear as shown below.

2. Assign materials.

Accept Structural Steel (typically the default material) for the model.



a. In the Steady-State Thermal schematic, right-click the Engineering Data cell and choose Edit.... TheEngineering Data tab opens and displays Structural Steel as the default material.

b. Click the Return to Project toolbar button.

3. Attach geometry.

a. In the Steady-State Thermal schematic, right-click the Geometry cell, and then choose Import Geo-metry.

b. Browse to open the file Rotor_Brake.agdb. This file is available on the ANSYS Customer Portal; goto http://support.ansys.com/training.

Define the Cyclic Symmetry Model

We now specify the cyclic symmetry for our quarter sector model (N = 4, 90 degrees) and prepare othergeneral aspects of modeling in the Mechanical application. To setup a cyclic symmetry analysis, Mech-anical uses a Cyclic Region object. This object requires selection of the sector boundaries, togetherwith a cylindrical coordinate system whose Z axis is colinear with the axis of symmetry, and whose Yaxis distinguishes the low and high boundaries.

1. Enter the Mechanical Application and set unit systems.

a. In the Steady-State Thermal schematic, right-click the Model cell, and then choose Edit.... TheMechanical Application opens and displays the model.

b. From the Menu bar , choose Units> Metric (mm, kg, N, s, mV, mA) .

2. Define the Coordinate System to specify the axis of symmetry.

a. Right-click Coordinate Systems in the tree and choose Insert> Coordinate System.

b. In the Details view of the newly-created Coordinate System, set Type to Cylindrical and Define Byto Global Coordinates.

3. Define the Cyclic Region object.

a. Right-click Model in the tree and choose Insert> Symmetry.

b. Right-click Symmetry and choose Insert> Cyclic Region. The direction of the Y-axis should be compat-ible with the selection of low and high boundaries. The low boundary is designated as the one with alower value of Y or azimuth.

c. Select the three faces that have lower azimuth for the low boundary. These faces are highlighted inblue in the figure below.

d. Select the three matching faces on the opposite end of the sector for the high boundary. These facesare highlighted in red in the figure below



4. Define Connections. Frictional contact exists between the rotor and brake pad, whereas bonded contactexists between the wall and the rotor.

a. Expand the Connections folder in the tree, then expand the Contacts folder. Within the Contactsfolder, two contact regions were detected automatically and displayed as Contact Region and ContactRegion 2.

b. Right-click the Contacts folder and choose Renamed Based on Definition. The contact region namesautomatically change to Bonded - Pad to Rotor and Bonded - Blade to Wall respectively.

c. Highlight Bonded - Pad to Rotor and in the Details view, set Type to Frictional. Note that the nameof the object changes accordingly.

d. In the Friction Coefficient field, type 0.2 and press Enter.

Note

For higher values of contact friction coefficient a damped modal analysis would beneeded. At a level of 0.2 damping effects are being neglected.

Generate the Mesh

In the following section well use mesh controls to obtain a mesh of regular hexahedral elements. TheCyclic Region object will guarantee that matching meshes are generated on the low and high boundariesof the cyclic sector.

Taking advantage of the shape and dimensions of the model, Named Selections will be used to choosethe edge selections for each mesh control.

Mesh control: Element Size on Pad-Wall-Rotor:



1. Create a Named Selection for this Mesh Control.

a. Right-click on Model and choose Insert> Named Selection.

b. Highlight the Selection object, and set Scoping Method to Worksheet.

c. Program the Worksheet, as shown below, to select the edges at 90 degrees of azimuth in the cylindricalcoordinate system, keeping those in the z-axis range [1mm, 6 mm] (to remove the thickness of thewall). To add rows to the Worksheet, right-click in the table and select the option from the flyout menus.

d. Click the Generate button. You should see 11 edges.

e. Rename the object to Edges for Wall Rotor Pad Sector Boundary. The selection should display asfollows:.

Note

It may be useful to undock the Worksheet window and tile it with the Geometryview as shown above.

2. Insert a Mesh Sizing control.

a. Right-click on Mesh and choose Insert> Sizing.

b. Set Scoping Method to Named Selection.

c. Choose the named selection defined in the previous step.



d. Set its Element Size to 0.5 mm.

e. Set Behavior to Soft.

Mesh control: Number of Divisions on Pad-Rotor:

1. Create a Named Selection to pick the circular edges in the orifice of the pad and rotor.

This Named Selection will pick the circular edges in the orifice of the pad and rotor, which is withina radius of 5 mm.



c. Rename the object to Edges for Rotor Pad Orifice.

d. Program the Worksheet, as shown below.

e. Click the Generate button. You should see 4 edges.

2. Insert a Mesh Sizing Control as before to select this Named Selection.




d. Set its Type to Number of Divisions and specify 9.

e. Set Behavior to Hard.

Mesh control: Element Size on Wall-Blade

1. Create a Named Selection object to pick the thicknesses of the Wall and Blade.



c. Rename the object to Edges for Wall Blade Thicknesses.

d. Program the Worksheet as shown below.








d. Set its Element Size to 1 mm.


Mesh Control: Number of Divisions on Blade - Longer Edges

1. Create a Named Selection object to pick the longer edges of the Blade.



c. Rename the object to Edges for Blade.









Mesh Control: Number of Divisions on Blade - Shorter Edges



1. Create a Named Selection object to pick the shorter edges of the Blade.



c. Rename the object to Edges for Blade 2.









Mesh Control: Method on Pad-Rotor-Wall-Blade

1. Insert a Sweep Method control.

a. Right-click Mesh in the tree and choose Insert> Method.

b. Select all the bodies by choosing Edit> Select All from the toolbar, then click the Apply button.

c. In the Details view, set Method to Sweep.

d. Set Free Face Mesh Type to All Quad.

Generate the Mesh

For convenience, select all 6 mesh controls defined, right-click and choose Rename Based on Definition.

Right-click Mesh in the tree and choose Generate Mesh. The mesh should appear as shown below:



Steady-State Thermal Analysis

We now proceed to define the boundary conditions for a thermal analysis featuring cyclic symmetry.Thermal boundary conditions are prescribed throughout the model while steering clear of the facescomprising the sector boundaries since temperature constraints are already implied there.

1. Define a convection interface.

a. Right-click Steady-State Thermal in the tree and choose Insert> Convection.

b. Select the outer faces of the Wall and the Blade as shown in the figure (8 faces).

c. Specify a Film Coefficient of air by right-clicking on the property and choosing Import TemperatureDependent upon which you choose Stagnant Air - Simplified Case.

2. Insulate the upper and lower faces of the Wall.

Select the upper and lower faces of the Wall, then right-click and choose Insert> Perfectly Insulated.

3. Apply a temperature load to the Pad and Rotor.



a. Select the remaining faces on the assembly on the Pad and the Rotor, then right-click and choose Insert>Temperature. Exclude any faces on the sector boundaries or in the frictional contact.

b. Type 100C as the Magnitude and press Enter.

4. Solve and review the temperature distribution.

a. Right-click Solution under Steady-State Thermal and choose Insert> Thermal> Temperature.

b. Solve the steady-state thermal analysis.

c. Review the temperature result by highlighting the Temperature result object.

Note

Although insignificant in this model, temperature variations and their effect on thestructural material properties are generally important to the formulation of physicallyaccurate models.

Static Structural Analysis

In this analysis, the brake is loaded onto the rotor in a single load step. The contact status is monitoredat various stages of loading and three points are selected as pre-stress conditions for subsequentmodal analyses. Because both contact and geometric nonlinearities are present, each pre-stress conditionwill present a different effective stiffness matrix to its corresponding modal analysis.

The solver uses restart points, generated in the static analysis, to record the snapshot of the nonlineartangent stiffness matrices and transfers them into the subsequent linear systems. This technique is re-ferred to as Linear Perturbation.



1. Apply the pressure and boundary conditions to engage the brake pad into the rotor.

a. Select the bottom face of the Pad as shown below. Right-click the Static Structural object in the treeand choose Insert> Pressure.

b. In the Details view, click the Magnitude flyout menu, choose Function, and specify: =time*time*4000,then press Enter. This represents a quadratic function reaching 4000 MPa by the end of the load step.

c. Set up the frictionless supports on the faces of Blade, Wall and Pad as shown below.

2. Configure the Analysis Settings.

a. Set Auto Time Stepping to On.

b. Set Define By to Substeps.

c. Set Initial Substeps to 30.

d. Set Minimum Substeps to 10.

e. Set Maximum Substeps to 30.

f. Set Large Deflection to On to activate geometric nonlinearities.

g. To ensure that Restart Points are generated, under Restart Controls, set Generate Restart Points toManual, and request to retain All Files for load steps and substeps. Maximum Points to Save shouldalso be set to All.

3. Proceed to solve the model using the standard procedure.



Reviewing the contact status changes during the course of the load application

The contact status will change with increasing loads from Near, to Sliding, to Sticking. A status changefrom Near to Sliding reflects the engagement of contact impenetrability conditions (normal direction).A change from Sliding to Sticking, reflects additional engagement of contact friction conditions (tangentialdirection). This progression will generally reflect an increased effective stiffness in the tangent stiffnessmatrix, which can be illustrated by a Force-deflection curve:

To review the contact status, insert a Contact Tool in the Solution folder. To display only the contactresults at the frictional contact, unselect Bonded - Wall To Blade in the Contact Tool Worksheet. Insertthree different Contact Status results with display times at 0.03, 0.5 and 0.8 seconds, which should revealthe progression in contact status as shown below (from left to right):

The legend for these contact status plots is as follows:

Yellow - Near

Light Orange - Sliding

Dark Orange - Sticking



Modal Analysis

There are three modal analyses to study the effect of contact status and stress stiffening on the freevibration response of the structure. Each of these will be based on a different restart point in the staticstructural analysis.

To see all available restart points, you can inspect the timeline graph displayed when the AnalysisSettings object of the Static Structural analysis is selected after solving. Restart points are denoted asblue triangle marks atop the graph:

To select the restart point of interest, go to the Pre-Stress (Static Structural) object under each ModalAnalysis. Make sure Pre-Stress Define By is set to Time and specify the time. The object will acknow-ledge the restart point in the Reported Loadstep, Reported Substep and Reported Time fields.

Configure the Modal analyses as follows:

In Modal 1 set Pre-Stress Time to 0.033 seconds.



Because the boundary conditions (that is, the frictionless supports) are automatically imported fromthe static analysis, we can proceed directly to solve.

Solving and Reviewing Modal Results

We'll monitor the lowest frequencies of vibration which belong to Harmonic Indices 0 (symmetric) and2 (anti-symmetric).

1. Right-click on the Solution folder of each Modal analysis and choose Solve.

2. When the solutions complete, go to the Tabular Data window of each modal analysis. You can inspectthe listing of modes and their frequencies. Because our structure has a symmetry of N=4, there will bethree solutions, namely for Harmonic Indices 0, 1 and 2.

3. In the Tabular Data window of each modal analysis, select the two rows for Harmonic Index 0 - Mode 1and Harmonic Index 2 - Mode 1. Right-click and choose Create Mode Shape Results.

The image below shows this view for the first Modal analysis:



An interesting alternative to this view is to see the sorted frequency spectrum. You may review thisby setting the X-Axis to Frequency on any of the Total Deformation results in each modal analysis:

At this point, each modal analysis should have two results for Total Deformation to inspect the firstMode of Harmonic Indices 0 and 2.

Recall the meaning of Harmonic Index solutions and how they apply to the model. Harmonic Index0 represents the constant offset in the discrete Fourier Series representation of the model and cor-responds to equal values of every transformed quantity, for example, displacements in X, Y and Zdirections, in consecutive sectors. Thus deformations that are axially positive in one sector will havethe same axially positive value in the next. The following picture compiles, from left to right, themode shapes for the Near, Sliding and Sticking status at Harmonic Index 0:

Notice how increased engagement of the frictional contact in the assembly has the effect of producinghigher frequency vibrations. Also, the mode of vibration goes from being localized at the contactinterface when the contact is Near, but is forced to distribute throughout the wall of the rotor asthe contact sticks.

Note

You may need to specify Auto Scale on the Results toolbar so the mode shapes areplotted as shown.



Harmonic Index 2 solutions correspond to N/2 for our sector (90 degrees or N = 4). This HarmonicIndex, sometimes called the asymmetric term in the Fourier Series, represents alternation of quant-ities in consecutive sectors. A positive axial displacement at a node in one sector becomes negativein the next, a radially outward displacement in one sector will become inward in the next, and soon. The following are the results for the first mode of this Harmonic Index:

The lowest mode shows nearly independent vibration of the rotor relative to the blade. On thehighest mode, sticking reduces this relative movement.

For a continued discussion on post-processing for Cyclic Symmetry and especially on features forpostprocessing degenerate Harmonic Indices (those between 0 and N/2), please see ReviewingResults for Cyclic Symmetry in a Modal Analysis in the Mechanical help.

End of tutorial.



Steady-State and Transient Thermal Analysis of a Circuit Board

Problem Description

The circuit board shown below includes three chips that produce heat during normal operation. Onechip stays energized as long as power is applied to the board, and two others energize and de-energizeperiodically at different times and for different durations. A Steady-State Thermal analysis and TransientThermal analysis are used to study the resulting temperatures caused by the heat developed in thesechips.

Features Illustrated

Linked analyses

Attaching geometry

Model manipulation

Mesh method and sizing controls

Constant and time-varying loads

Solving

Time-history results

Result probes

Charts

Procedure

1. Create analysis system.



You need to establish a transient thermal analysis that is linked to a steady-state thermal analysis.


b. From the Toolbox, drag a Steady-State Thermal system onto the Project Schematic.

c. From the Toolbox, drag a Transient Thermal system onto the Steady-State Thermal system suchthat cells 2, 3, 4, and 6 are highlighted in red.

d. Release the mouse button to define the linked analysis system.

2. Attach geometry.

a. In the Steady-State Thermal schematic, right-click the Geometry cell, and then choose Import Geo-metry.

b. Browse to open the file BoardWithChips.x_t. This file is available on the ANSYS Customer Portal;go to http://support.ansys.com/training.

3. Continue preparing the analysis in the Mechanical Application.

a. In the Steady-State Thermal schematic, right-click the Model cell, and then choose Edit. The Mechan-ical Application opens and displays the model.

b. For convenience , use the Rotate toolbar button to manipulate the model so it displays as shown below.



Note

You can perform the same model manipulations by holding down the mouse wheelor middle button while dragging the mouse.

c. From the Menu bar , choose Units> Metric (m, kg, N, s, V, A) .

4. Set mesh controls and generate mesh.

Setting a specific mesh method control and mesh sizing controls will ensure a good quality mesh.

Mesh Method:

a. Right-click Mesh in the tree and choose Insert> Method.

b. Select all bodies by choosing Edit> Select All from the toolbar, then clicking the Apply button in theDetails view.

c. In the Details view, set Method to Hex Dominant, and Free Face Mesh Type to All Quad.

Mesh Body Sizing Board Components:

a. Right-click Mesh in the tree and choose Insert> Sizing.

b. Select all bodies except the board by first enabling the Body selection toolbar button, then holdingthe Ctrl keyboard button and clicking on the 15 individual bodies. Click the Apply button in the Detailsview when you are done selecting the bodies.

c. Change Element Size from Default to 0.0009 m.

Mesh Body Sizing Board:

a. Right-click Mesh in the tree and choose Insert> Sizing.

b. Select the board only and change Element Size from Default to 0.002 m.

Generate Mesh:

Right-click Mesh in the tree and choose Generate Mesh.



5. Apply internal heat generation load to chip.

The chip on the board that is constantly energized represents an internal heat generation load of

5e7 W/m3.

a. Select the chip shown below by first enabling the Body selection toolbar button, then clicking on thechip.

b. Right-click Steady-State Thermal in the tree and choose Insert> Internal Heat Generation.

c. Type 5e7 in the Magnitude field and press Enter.

General items to note:

The applied loads are shown using color coded labels in the graphics.

Time is used even in a steady-state thermal analysis.

The default end time of the analysis is 1 second.



In a steady-state thermal analysis, the loads are ramped from zero. You can edit the table of load vs.time to modify the load behavior.

You can also type in expressions that are functions of time for loads.

6. Apply a convection load to the entire circuit board.

The entire circuit board is subjected to a convection load representing Stagnant Air - SimplifiedCase.

a. Select all bodies by choosing Edit> Select All.

b. Choose Convection from the Environment toolbar.

c. Import temperature dependent convection coefficient and choose Stagnant Air - Simplified Case.

Note that the Ambient Temperature defaults to 22oC.

i. Click the flyout menu in the Film Coefficient field and choose Import Temperature Dependent(adjacent to the thermometer icon).

ii. Click the radio button for Stagnant Air - Simplified Case, then click OK.

7. Prepare for a temperature result.

The resulting temperature of the entire model will be reviewed.

Right-click Solution in the tree under Steady-State Thermal and choose Insert> Thermal> Temperature.

8. Solve the steady-state thermal analysis.

Choose Solve from the toolbar.

9. Review the temperature result.

Highlight Temperature in the tree.

You have completed the steady-state thermal analysis, which is the first part of the overall objectivefor this tutorial. You will perform the transient thermal analysis in the remaining steps.

Items to note in preparation for the transient thermal analysis:

If you highlight Initial Temperature under Transient Thermal in the tree, you will notice in the Detailsview, the read only displays of Initial Temperature and Initial Temperature Environment. In general,the initial temperature can be:



Uniform Temperature - where you specify a temperature for all bodies in the structure at time = 0,or

Non-Uniform Temperature - (as in this example) where you import the temperature specification attime = 0 from a steady-state analysis.

The initial temperature environment is from the steady-state thermal analysis that you just performed.By default the last set of results from the steady-state analysis will be used as the initial condition. Youcan specify a different set (different time point) if multiple result sets are available.

10. Specify a time duration for the transient analysis.

A time duration of the transient study will be 200 seconds.

Under Transient Thermal, highlight the Analysis Settings object and enter 200 in either the Step EndTime field in the Details view or in the End Time column in the Tabular Data window. Also note andaccept the default initial, maximum, and minimum time step controls for this analysis.

11. Apply internal heat generation to simulate on/off switching on first chip.

A chip on the board is energized between 20 and 40 seconds and represents an internal heat gen-

eration load of 5e7 W/m3 during this period.


b. Right-click Transient Thermal in the tree and choose Insert> Internal Heat Generation.

c. Enter the following data in the Tabular Data window:



Time = 0; Internal Heat Generation = 0

Note

Enter each of the following sets of data in the row beneath the end time of 200 s.


Time = 20.1; Internal Heat Generation = 5e7

Time = 40; Internal Heat Generation = 5e7

Time = 40.1; Internal Heat Generation = 0

The Graph window reflects the data that you entered.

General items to note:

Loads can be specified as one of three types:

Constant remains constant throughout the time history of the transient.

Tabular (Time) (as in this example) define a table of load vs. time.

Function enter a function such as =10*sin(time) to define a variation of load with respect totime. The function definition requires you to start with a = as the first character.

12. Apply internal heat generation to simulate on/off switching on second chip.

Another chip on the board is energized between 60 and 70 seconds and represents an internal heat

generation load of 1e8 W/m3 during this period.




b. Right-click Transient Thermal in the tree and choose Insert> Internal Heat Generation.

c. Enter the following data in the Tabular Data window:


Note

Enter each of the following sets of data in the row beneath the end time of 200 s.


Time = 60.1; Internal Heat Generation = 1e8

Time = 70; Internal Heat Generation = 1e8

Time = 70.1; Internal Heat Generation = 0

The Graph window reflects the data that you entered.

13. Prepare for a temperature result.

The resulting temperature of the entire model will be reviewed.

Right-click Solution in the tree under Transient Thermal and choose Insert> Thermal> Temperature.

14. Solve the transient thermal analysis.



Click the right mouse button again on Solution and choose Solve. The solution is complete when greenchecks are displayed next to all of the objects. You can ignore the Warning message and click the Graphtab.

15. Review the time history of the temperature result for the entire model.

Highlight the Temperature object. The time history of the temperature result for the entire model isevaluated and displayed.

The Tabular Data window shows the min/max values of temperature at a time point.

By moving the mouse, you can move the bar along the Graph as shown, to any time, click the rightmouse button and Retrieve this Result to review the results at a particular time.

You can also animate the solution.

16. Review the time history of the temperature result for each of the chips.

Temperature probes are used to obtain temperatures at specific locations on the model.

a. Right-click Solution and choose Insert> Probe> Temperature.

b. Select the chip to which internal heat generation was applied in the steady state analysis and click theApply button in the Details view.

c. Follow the same procedure to insert two more probes for the two chips with internal heat generationsin the transient thermal analysis.

d. Right-click Solution or Temperature Probe and choose Evaluate All Results.

17. Plot probe results on a chart.

a. Select the three temperature probes in the tree and select the New Chart and Table button from thetoolbar.

A Chart object is added to the tree.



b. Right-click in the white space outside the chart in the Graph window and choose Show Legend.

c. In the Details view, you can change the X Axis variable as well as selectively omit data from being dis-played.

You have completed the transient thermal analysis and accomplished the second part of the overallobjective for this tutorial.

End of tutorial.



Delamination Analysis using Contact Based Debonding Capability

Problem Description

This tutorial demonstrates the use of Contact Debonding feature available in Mechanical by examiningthe displacement of two 2D parts on a double cantilever beam. This same problem is demonstrated inVM255. The following example is provided to demonstrate the steps to setup and analyze the samemodel using Mechanical.

As illustrated below, a two dimensional beam has a length of 100mm and an initial crack of length of30mm at the free end that is subjected to a maximum vertical displacement (Umax) at the top and

bottom of the free end nodes. Two vertical displacements, one positive and one negative, are appliedto determine the vertical reaction at the end point. The point of fracture is at the vertex of the crackand the interface edges.

This tutorial also examines how to prepare the necessary materials that work in cooperation with theContact Debonding feature.


Engineering Data/Materials




Contact Regions

Contact Debonding

Procedure

1. Create static structural analysis.

a. Open ANSYS Workbench.

b. On the Workbench Project page, drag a Static Structural system from the Toolbox to the ProjectSchematic. The Project Schematic should appear as follows. The properties window does not displayunless you have made the required selection; right-click a cell and select Properties.

2. Define materials.

a. In the Static Structural schematic, right-click the Engineering Data cell and choose Edit. The Engin-eering Data tab opens and displays Structural Steel as the default material.

b. Click the box below the field labeled "Click here to add new material" and enter the name "InterfaceBody Material".

c. Expand the Linear Elastic option in the Toolbox and right-click Orthotropic Elasticity. Select IncludeProperty. The required properties for the material are highlighted in yellow.



d. Define the new material by entering the following property values and units of measure into the cor-responding fields.

UnitValueProperty

MPa1.353E+05Youngs Modulus X Direction

MPa9000Youngs Modulus Y Direction

MPa9000Youngs Modulus Z Direction

NA0.24Poissons Ratio XY

NA0.46Poissons Ratio YZ

NA0.24Poissons Ratio XZ

MPa5200Shear Modulus XY

MPa0.0001Shear Modulus YZ

MPa0.0001Shear Modulus XZ

Once complete, the properties for the material should appear as follows.

e. Now you need to create a new Material that specifies the formulation used to introduce the fracturemechanism. For this tutorial, the Cohesive Zone Material (CZM) method is used. Click the field labeled"Click here to add new material" and enter the name CZM Crack Material.



f. Expand the Cohesive Zone option in the Toolbox and right-click Fracture-Energies based Debonding.Select Include Property. The required properties for the material are highlighted in yellow.

g. Define the new material by entering the following property values and units of measure into the cor-responding fields.

UnitValueProperty

NANoTangential Slip Under Normal Compression

Pa1.7E+06Maximum Normal Contact Stress

Jm^-2

280Critical Fracture Energy for Normal Separation

Pa1E-30Maximum Equivalent Tangential ContactStress

Jm^-2

1E-30Critical Fracture Energy for Tangential Slip

s1e-8Artificial Damping Coefficient

The properties for the material should appear as follows.



3. Attach geometry.

a. In the Static Structural schematic, right-click the Geometry cell and choose Import Geometry>Browse.

b. Browse to the proper location and open the file 2D_Fracture_Geom.agdb. This file is available onthe ANSYS Customer Portal; go to http://support.ansys.com/training.

c. Right-click the Geometry cell and select Properties. In the Properties window, set the Analysis Typeproperty to 2D.

The Project Schematic should appear as follows:

4. Launch Mechanical. Right-click the Model cell and then choose Edit. (Tip: You can also double-click thecell to launch Mechanical).

5. Define unit system. From the menu bar in Mechanical, select Units>Metric (mm, kg, N, s, mV, mA).

6. Define 2D behavior.

a. Select the Geometry folder.

b. In the Details pane, set the 2D Behavior property to Plane Strain. This constrains all of the UZ degreesof freedom. See the 2D Analyses section for additional information about this property.



7. Apply material.

a. Expand the Geometry folder and select the Part 2 folder.

b. In the Details pane, set the Assignment property to Interface Body Material. Selecting the Part folderallows you to assign the material to both parts at the same time.

8. Define contact region.



a. Expand the Connections folder and the Contacts folder. A Contact Region object was automaticallygenerated for the entire interface of the two parts.

b. Select the Edge selection filter (on the Graphics Toolbar) and highlight an edge in the center of themodel. Using the Depth Picking tool, select the first rectangle in the stack, and then scope the edge asthe geometry (Apply in the Contact property).

This tutorial employs the Depth Picking tool because of the close proximity of the two edgesinvolved in the interface. As illustrated here, the graphics window displays a stack of rectanglesin the lower left corner. The rectangles are stacked in appearance, with the topmost rectanglerepresenting the visible (selected) geometry and subsequent rectangles representing additionalgeometry selections. For this example, the topmost geometry is the "high" edge.

c. Select the Edge selection filter and highlight an edge in the center of the model. Using the DepthPicking tool, select the second rectangle in the stack, and then scope the edge as the geometry (Applyin the Target property).

Verify that Bonded is selected as the contact Type and that Pure Penalty is set as the Formu-lation.



d. Rename the contact "Body".

9. Define Mesh Options and Controls.

a. Select the Mesh object. Define the following Mesh object properties:

Set Use Advanced Size Function (Sizing category) to Off.

Enter an Element Size (Sizing category) of 0.750.

Set Element Midside Nodes (Advanced category) to Kept.

b. Right-click the Mesh object and select Insert>Sizing. This mesh sizing control should be scoped to thefour side edges.



c. In the Details view, enter 0.75 mm as the Element Size.

d. Select the Edge selection filter (on the Graphics Toolbar) and highlight an edge in the center of themodel. Use the Depth Picking tool and, holding the Ctrl key, select both rectangles in the lower leftcorner of the graphics window. Continue to hold the Ctrl key, and select an edge of the crack. Again,use the Depth Picking tool and select both rectangles in the lower left corner of the graphics window.Still holding the Ctrl key, select the top and bottom edges on the model.

e. Right-click the Mesh object and select Insert>Sizing. This mesh sizing control should be scoped to six(top and bottom and the four interface edges) edges.

f. In the Details view, enter 0.5 mm as the Element Size.

g. Right-click the Mesh object and select Generate Mesh.

10. Specify Contact Debonding object.

a. Insert a Fracture folder into the tree by highlighting the Model object and then selecting the Fracturebutton on the Model Context Toolbar.



b. Right-click and select Insert>Contact Debonding. You could also select the Contact Debondingbutton on the Fracture Context Toolbar.

c. In the Details pane, set the Material property to CZM Crack Material.



d. In the Details pane, set the Contact Region property to Body.

The Contact Debonding object is complete.



11. Configure the Analysis Settings.

a. Select the Analysis Settings object.

b. Set the Auto Time Setting property to On and then enter 100 for the Initial Substeps, MinimumSubsteps, and Maximum Substeps properties.

12. Apply boundary conditions.

a. Select the Edge selection filter and select the two edges on the side of the model that is opposite ofthe crack. Select one edge, press the Ctrl key, and then select the next edge.



b. Highlight the Static Structural object, select the Supports menu on the Environment Context Toolbar,and then select Fixed Support.

c. Highlight the Static Structural object. With the Vertex selection filter active, select the vertex illustratedbelow, select the Supports menu and then select Displacement.

In the Details pane, enter 10 (mm in the positive Y direction) as the loading value for the YComponent property.

d. Create another Displacement. With the Vertex selection filter active, select the bottom vertex, andthen select Supports>Displacement. Enter -10 (mm in the negative Y direction) as the loading valuefor the Y Component property.



13. Specify result objects and solve.

a. Highlight the Solution object, select the Deformation menu on the Solution Context Toolbar, andthen select Directional Deformation.

b. Under the Definition category in the Details view, set the Orientation property to Y Axis.

c. Highlight the Solution object, select the Probe menu on the Solution Context Toolbar, and then selectForce Reaction.

d. Select Displacement for the Boundary Condition property of the probe.

e. Click the Solve button.

14. Review the results. Highlight the Directional Deformation and Force Reaction objects. Results appearas follows:



You may wish to validate results against those outlined in the verification test case (VM255). This ismost easily accomplished by creating User Defined Results using the Worksheet.

End of tutorial.



Interface Delamination Analysis of Double Cantilever Beam

Problem Description

This tutorial demonstrates the use of Interface Delamination feature available in Mechanical by examiningthe displacement of two 2D parts on a double cantilever beam. This same problem is demonstrated inVM248. The following example is provided to demonstrate the steps to setup and analyze the samemodel using Mechanical.

As illustrated below, a two dimensional beam has a length of 100mm and an initial crack of length of30mm at the free end that is subjected to a maximum vertical displacement (Umax) at the top and

bottom of the free end nodes. Two vertical displacements, one positive and one negative, are appliedto determine the vertical reaction at the end point. The point of fracture is at the vertex of the crackand the interface edges.

This image illustrates the dimension of the model.

This tutorial also examines how to prepare the necessary materials and mesh controls that work in co-operation with the Interface Delamination feature.


Engineering Data/Materials




Match Control

Interface Delamination

Procedure

1. Create static structural analysis.

a. Open ANSYS Workbench.

b. On the Workbench Project page, drag a Static Structural system from the Toolbox to the ProjectSchematic. The Project Schematic should appear as follows. The properties window does not displayunless you have made the required selection; right-click a cell and select Properties.

Note

The Interface Delamination feature is only available for Static Structural and TransientStructural analyses.

2. Assign materials.

This analysis requires the creation of the proper materials using the Engineering Data feature ofWorkbench. We will define a new Orthotropic Elastic material for the model as well as a CohesiveZone Bilinear material for the Interface Delamination feature.

a. In the Static Structural schematic, right-click the Engineering Data cell and choose Edit. The Engin-eering Data tab opens and displays Structural Steel as the default material.

b. Click the box labeled "Click here to add new material" and enter the name "Interface Body Material".

c. Expand the Linear Elastic option in the Toolbox and right-click Orthotropic Elasticity. Select IncludeProperty. The required properties for the material are highlighted in yellow.



d. Define the new material by entering the following property values and units of measure into the cor-responding fields.

UnitValueProperty

MPa1.353E+05Youngs Modulus X Direction

MPa9000Youngs Modulus Y Direction

MPa9000Youngs Modulus Z Direction

na0.24Poissons Ratio XY

na0.46Poissons Ratio YZ

na0.24Poissons Ratio XZ

MPa5200Shear Modulus XY

MPa0.0001Shear Modulus YZ

MPa0.0001Shear Modulus XZ

The properties for the material should appear as follows:

e. Click the box labeled "Click here to add new material" and enter the name CZM Material. This mater-ial will specify the formulation used to introduce the fracture mechanism (Cohesive Zone Materialmethod).



f. Expand the Cohesive Zone option in the Toolbox and right-click Exponential for InterfaceDelamination. Select Include Property. The required properties for the material are highlighted inyellow.

g. Define the new material by entering the following property values and units of measure into the cor-responding fields.

UnitValueProperty

Pa2.5E+07Maximum Normal Traction

m4E-06Normal Separation Across the Interface

m1Shear Separation at Maximum ShearTraction

The properties for the material should appear as follows.

3. Attach geometry.

a. In the Static Structural schematic, right-click the Geometry cell and select Import Geometry>Browse.

b. Browse to the proper location and open the file 2D_Fracture_Geom.agdb. This file is available onthe ANSYS Customer Portal; go to http://support.ansys.com/training.

c. Right-click the Geometry cell and select Properties. In the Properties window, set the Analysis Typeproperty to 2D.

The Project Schematic should appear as follows:



4. Launch Mechanical. Right-click the Model cell and then choose Edit. (Tip: You can also double-click thecell to launch Mechanical).

5. Define unit system. From the menu bar in Mechanical, select Units>Metric (mm, kg, N, s, mV, mA).

6. Define 2D behavior.

a. Highlight the Geometry folder.

b. In the Details pane, specify the 2D Behavior property as Plane Strain. This constrains all of the UZdegrees of freedom. See the 2D Analyses section for additional information about this property.



ANSYS Mechanical Tutorials

Documents

Transcript of ANSYS Mechanical Tutorials