RD 3DSliderCrank

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3D Slider Crank Tutorial(Basic)


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Table of Contents

Getting Started ........................................................................................... 4

Objective .............................................................................................. 4

Audience .............................................................................................. 6

Prerequisites......................................................................................... 5

Procedures ........................................................................................... 5

Setting Up Your Simulation Environment ................................................... 6

Task Objective ...................................................................................... 6

Estimated Time to Complete ................................................................ 6

Starting RecurDyn ................................................................................ 7

Understanding the Interface ................................................................. 9

Changing the Gravitational Force Direction ........................................ 12

Changing the Working Plane .............................................................. 12Creating Geometry ................................................................................... 14

Task Objective .................................................................................... 14

Estimated Time to Complete .............................................................. 14

Modeling the Ground Bracket ............................................................. 15

Saving Your Model ............................................................................. 21

Modeling the Crank ............................................................................ 22

Saving Your Model ............................................................................. 30

Creating the Connecting Rod ............................................................. 30

Modeling the Slider ............................................................................. 32Saving Your Model ............................................................................. 38

Creating Joints ......................................................................................... 39

Task Objective .................................................................................... 39


Creating the Revolute Joint ................................................................ 40

Adjusting the Icon and Marker Size .................................................... 41

Creating Two Spherical Joints ............................................................ 41

Creating the Translational Joint .......................................................... 43

Creating a Motion on the Revolute Joint ............................................. 44

Performing Analysis ................................................................................. 47


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Task Objective .................................................................................... 47


Performing Dynamic/Kinematic Analysis ............................................ 48

Working with Animations .......................................................................... 49

Task Objectives .................................................................................. 49

Estimated Time to Complete .............................................................. 49About the Animation Toolbar .............................................................. 50

Playing Animations ............................................................................. 50

Saving the Animation as an AVI File .................................................. 51

Tracing the Paths of a Point on the Moving Bodies ............................ 52

Plotting ..................................................................................................... 56

Task Objective .................................................................................... 56


Creating a Plot .................................................................................... 57

Plotting in Multiple Panes ................................................................... 58Loading an Animation ......................................................................... 59


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Getting Started

Objective

In this introductory tutorial, you will learn how to:

Set up a model with the correct units and environment Create bodies with geometric detail Add joints and associated input motions Analyze the model to investigate the effects of motion and forces on it. Communicate the results of your simulation as:

X-Y plots

Animations that can be played interactively within RecurDyn

AVI files that can be inserted into PowerPoint presentations

The target model is a 3D slider-crank mechanism.This mechanism is used to convert an input rotarymotion to an output translational motion. You willsee how the combination of moving bodies and fourkinematic joints can produce a complex relationship

between the input and output motions.

Chapter

1


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Audience

This tutorial is an excellent starting point for the engineer who is using RecurDyn for the firsttime. The basic tasks that are needed for all simulations are explained carefully.

Prerequisites

Because this is an introductory tutorial, we assume that you have no prior experience withRecurDyn. We assume that you have a basic knowledge of physics.

Procedures

The tutorial is comprised of the following procedures. The estimated time to complete eachprocedure is shown in the table.

Estimated Time to Complete

This tutorial takes approximately 75 minutes to complete.

ProceduresTime

(minutes)Simulation environment setup 5

Geometry creation 35

Joint creation 10

Analysis 5

Animation/AVI 10

Plotting 10

Total: 75


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Setting Up Your Simulation

Environment

Task Objective

Learn how to set up the simulation environment, including units, materials, gravity, and theworking plane.


5 minutes

Chapter

2


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Starting RecurDyn

To start RecurDyn and create a new model:

1. On your Desktop, click the RecurDyn tool .RecurDyn starts up and the New Model dialog box appears.

2. Enter the name of the new model as Slider_Crank_3D.3. Leave the units at the default values.4. ClickOK.

Tip: Allowed Characters for Model Name

You cannot use spaces or special characters in the model name. You can use the underscorecharacter to add spacing to improve the readability of the name.


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Tip: How to set user material library

If you want to use a user material, you can import a bin file that RecurDyn exports (refer tothe Material Property command under the Subentity menu.)

To import a user material:

1. In the New Model dialog box, clickUser Material Library.2. ClickAdd to select a bin file, and then select Open.3. ClickOK.

Tip: Other ways to create a new model

To create a new model in RecurDyn, you can do one of the following:

In the tool bar, click the New tool. From the File menu, clickNew. Use the shortcut key (Ctrl + N).


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Understanding the Interface

The RecurDyn interface consists of several basic areas as shown in the figure below. Youcan turn on and off the display of any areas and rearrange the areas any way you want. Eacharea is explained below.

Using the Toolkit Bar

The toolkit bar provides you with all the tools you need to create a model, including thegeometries, constraints, and motions. It divides the tools into subcategories to make it easierfor you to find the tools.

To select a tool:

1. Click the tool subcategory, such as Body or Force.The set of tools in that category appears.

2. Click the desired tool.Using the Toolbars

RecurDyn provides a set of toolbars at the top to let you quickly perform operations on yourmodel and change modes. These are the same operations that you can perform using themenus.

Using the Database Window

You can view all the data and entities in your model using the Database window. In addition,you can:


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View and change the properties of each entity.

Make constraints and forces inactive and reactivate them.

Change the display modes of individual bodies.

Change to the edit mode of subsystems, bodies, and profiles.

To view the entities in your model:

Click the + in front of an entity in the database window.

Using the Working Model Window

The working model window is where you build your model. You can use the tools to zoomand rotate your model and set the working plane on which you build your model.

Using the Modeling Option and Input Toolbars

The two modeling toolbars at the bottom of the window help you create your model:

The Modeling Option toolbar sets the options for the current operation.

Modeling Input toolbar lets you enter coordinates or a parametric point name andvalue, depending on the required input.

For example, if you are creating a cylinder, in the Modeling Option toolbar, you set themethod for creating the cylinder (define two points or define two points and a radius). Then,you enter the values for the two points or the two points and a radius in the Modeling Input

Command toolbar. The toolbars are shown below.

To use the toolbars together to create your model:

1. Select an entity to create, such as a cylinder.2. From the Modeling Option Toolbar, select a creation method, such as Point, Point,

Radius.

3. Enter the first point in the Modeling Input toolbar.4. Press Enter or click (on the right of the toolbar).5. Enter the second point in the Modeling Input toolbar.

6. PressEnteror click .


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Status Bar

The Status bar provides information about the state of your model

System Modes in RecurDyn

There are four modes in which you can work in RecurDyn:

Model-EditingWork on the entire model. Lets you create objects in your model atthe top level in the model hierarchy.

Subsystem-EditingWork on the all of the entities in a subsystem. Lets you createobjects in your model that belong to a logical subsystem in your model. A subsystemcan contain a group of entities that are created using the process automation of aRecurDyn toolkit, such as a belt, chain, or track assembly.

Body-EditingEdit a particular entity in your model, such as ground, a link, orforce.

Profile-EditingChange the properties associated with a particular entity in yourmodel.

By default, RecurDyn is in model-editing mode. You switch between the modes depending onthe operations that you want to perform. In this tutorial, youll switch to body-editing mode toedit the ground and then you will switch to the profile-editing mode as needed to creategeometry.

You change to body- or property-editing:

In the Database window, right-click an entity, and from the menu that appears, clickEdit.

In the working model window, double-click a subsystem, body, or profile geometry.

Click on one of the mode tools on the toolbar.


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Changing the Gravitational Force Direction

In this tutorial, you will change the gravitational force of theZ directions.

To change the gravitational force direction:

1. From the Settings menu, select Gravity.2. Set Load Default Gravity toZ.

3. ClickLoad or fill out the value and direction of theZ to the values: X: 0 Y: 0 Z: -9806.65

Changing the Working PlaneYou will now use the Working Plane tool on the toolbar to change the working plane so it isin the XZ plane of the inertia reference frame.

To change the working plane:

1. In the toolbar, click the combo box next to the Working Plane Change tool.2. Select Change to XZ.

The Working Plane tool can only change the working plane aboutthe inertial reference frame. If you want to change the workingplane about another plane, see the next Tip.


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Tip: How to select the working plane

You can set the working plane about any grid or the working plane itself.

To set the working plane about any grid:

1. From the View menu, point toWorking Plane, and then selectSetup.

The Working Plane Setup dialog box appears.

2. Click the Pl button.

3. Select the plane of a marker or flat face.4. ClickOK.

You can set the working plane and the grid settings in this dialog box.

To change a working plane about the selected working plane:

1. Click the combo box next to the Working PlaneChange tool.

2. Select one of the working planes.


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Creating Geometry

Task ObjectiveIn this chapter, you will create geometry to define the 3D slider crank, which consists of:

Grounded bracket

Crank

Connecting rod

Slider bodies


35 minutes

Chapter

3

Crank

Groundedbracket

Connecting

rod

Slider


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Modeling the Grounded Bracket

In this section, you create geometry to define the grounded bracket. You will create thebracket using two boxes, two cylinders, and two extrusions. This will also introduce you to the

basics of using the toolkits to create geometry.

To change to body-editing mode for ground:

In the Body toolkit, click the Ground tool to enter the Body-Edit mode forthe ground body of the model.


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To set the grid size to 10 in both the X and Z directions:

In the second row of the upper toolbar, set the gridsize to 10 in both text boxes by placing the cursor ineach text box, clicking the left mouse button, and

typing 10, and then pressing the Enterkey.

To create the box geometry:

1. In the Solid and Markertoolkit, click the Box tool.2. Set the Modeling Option toolbar to Point, Point, Depth.3. In the modeling window, click these points and input a depth for

both boxes in the Modeling Input toolbar. (Note that you can alsoenter the points in the Modeling Input toolbar. For more on using

the toolbars, see Using the Modeling Option and Input Toolbarsin Chapter2.)

Box1:

Point1: 100, 0, -50 Point2: -100, 0, 0 Depth: 200

Box2:

Point1: -150, 0, 200 Point2: -100, 0, -50 Depth: 200

The boxes you create should look like the following:


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To create the cylinder geometry:

Since you will create two cylinders at one time you will use the Auto Operation mode toautomatically remain in the cylinder creation mode. The Auto Operation mode can beused with any input command and it can save a substantial amount of time when you are

creating many entities of the same type.

1. Click on the Auto Operation tool to activate the Auto Operation input mode.2. In the Solid and Markertoolkit, click the Cylindertool.3. Set the Modeling Option toolbar to Point, Point, Radius.4. In the modeling window, click these points and input a depth for

both cylinders in the Modeling Input toolbar:

Cylinder 1:

Point1: -100, 0, 170 Point2: -80, 0, 170 Radius: 20

Cylinder 2:

Point1: -80, 0, 170 Point2: -40, 0, 170 Radius: 5

5. Click on the Auto Operation tool again to exit the Auto Operation input mode.6. Click on the Escape (Esc) key to exit the Cylinder input tool.

The cylinders you created should look like the following:


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Tip: How to modify the geometry properties

If you want to modify the parameters of geometry, you can modify them using theProperty dialog box.

The following shows the properties for a box and a cylinder.

To create an extrusion:

1. From the toolbar, click the combo button next to the Working Plane tool and selectChange to YZ to define the working plane as the YZ plane of inertia referenceframe.

2. In theBody toolkit, click theGeneral tools.3. In the Profiletoolkit, click the Profile tool.

4. To create 2-D line geometry for the extrusionprofile, in the Profile toolkit, click2D Line.

5. Create the profile using the points below. The


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profile that should result is shown in the figure below. You may find that inputtingthe values in the Modeling Input toolbar is the most efficient way to enter the values.

Point X, Y

1 -100, 0

2 -100, -50

3 100, -50

4 100, 0

5 30, 0

6 30, -20

7 60, -20

8 60, -40

9 -60, -40

10 -60, -20

11 -30, -20

12 -30, 0

13 -100, 0

6. To finish the creation of the profile, right-click the working model window, and fromthe menu that appears, clickFinish Operation.

7. You can edit the 2-D line by using the Property dialog box for the profile just createdto correct any errors.

8. Exit the profile-creation mode (see the tip below).


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Tip: How to exit a mode

There are two ways to exit a sub-mode:

Right-click the working model window, and from the menu that appears, clickExit.

From the Tool menu, clickExit.To create the solid extrusion:

1. Define the working plane as the YZ plane. (Tip: Click the combo button next to theWorking Plane tool and select Change to YZ.)

2. In the Profile toolkit, click the Extrude tool.3. In the working window, click the profile line that you just

created. It will be a vertical line at an x value of 0.

4. Click the point on ground or input a distance in theModeling Input toolbar:

Point1: 0, 250, 0

or

Distance: 250

The bracket should now look like the figure on the next page. You may need to rotate it to see

it (in the working model window, type rand hold down the left mouse button to rotate).

To move the extrusion geometry to the right:

1. Define the working plane as the XZ plane.2. On the toolbar, click the Object Control(Basic)tool.3. Select the Extrusion geometry.4. Enter the Offset Value of100.5. Click+X button.


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6. Close the Object Control dialog box (use the x in the upper right corner).The extrusion geometry moves from here:

To here:

7. Exit the body-editing mode for the Ground body by right-clicking the working modelwindow and clickingExit.

Saving Your ModelTake a moment to save the work youve done so far.

To save your model:

1. From the File menu, clickSave.2. Enter the location and name for the file.3. Select OK.


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Modeling the Crank Body

Now you will create the crank.

To define the working plane:

Define the working plane as the YZ plane.

To create the crank body:

1. In the Body toolkit, click the Link tool.2. Click these points:

Point1 [ 0, 0, 30 ]

Point2 [ 0, 0, 170 ]

Your link geometry should now look like the one shown below.


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To change the name of the body:

1. Right-click the working window over the model, point to Properties, point to Bodies,and and then clickBody1.

The Properties dialog box appears.

2. Click the General tab.3. Change the body name from Body1 to Crank.4. ClickOK.


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Tip: How to use the Database window to access properties

You can use the Database window to access theproperties.

To use the Database window:

1. In the Database window, right-click an object.2. From menu that appears, clickProperty

Modifying the Link Geometry of the Crank

In this section, youll change the radius of the crank.

To modify the link geometry of the crank:

1. Change to Body-Editing Mode of the Crankbody:a. In the Database window, right-clickCrank.b. From the menu that appears, clickEdit.

The link is now the only geometry in the workingmodel window.

2. While still in the body-editing mode of the Crank, displaythe Link1 geometry property dialog box:

a. In the Database window, right-clickLink1.b. From the menu that appears, clickProperty.

3. Modify the linkProperties (by default the units are in mm): First Radius: 20 Second Radius: 25

Depth: 20


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Creating Sphere (Ellipsoid) Geometry and Uniting it with the Link Geometry of the

Crank

In this section, youll create ellipsoid geometry and use the Boolean unite command to unite itwith the link geometry you created earlier.

To create the ellipsoid:

1. While still in the body-editing mode of the Crank, selectEllipsoid from the Solid andMarkertoolkit.

2. Click on a point and enter a radius for the sphere: Point: 0, 0, 30

Distance: 15


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To unite the ellipsoid and crank:

1. In the Boolean toolkit, click the Unite tool.2. Select the Crank geometry and then the Ellipsoid geometry.

(You can enter their names in the Modeling Input toolbar aswell).

The crank geometry and the ellipsoid were listedseparately in the Database window

and now appear under a subcategory of Unite1.

Tip: How to work with Boolean operations

A Boolean operation can work between two geometries only.The united geometry is displayed asUnite1 in theDatabase window.

You can select the entities in the working model window.

Tip: How to undo a Boolean Unite Operation

You can restore the united geometry to its previous state using the Delete Top Node onlymenu shown below. In this case, the top node would be the Unite1.

To delete the top node:

1. Right-click the node.2. ClickDelete Top Node only.


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Performing a Boolean Subtract Operation

In this section, you will create another ellipsoid geometry and subtract it from the crankgeometry you created in the previous section to create a hole for locating the attachment pointof the connecting rod.

To create the ellipsoid geometry and move it:

1. While still editing the crank, in the Solid and Markertoolkit, create Ellipsoidgeometry:

Point: 0, 0, 30

Distance: 152. Select Ellipsoid2.3. Click the Object Control(Basic) tool to open the Object Control dialog box.

4. In Offset Value, enter 5.5. Click+X.

The Ellipsoid moves to the right 5 pixels as shown below.

6. Exit the Object Control dialog box (click the X in the upper right corner).7. In the Boolean toolkit, click the Subtract tool.8. Select Unite1 and then Ellipsoid2.


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RecurDyn subtracts the ellipsoid from the crank, as shown in the next figure. A databaseobject of Unite1 now appears under a top node of Subtract1 in the Database window as alsoshown next.

Adding a Collar to the Crank

In this section, youll now create some cylinder geometry to define the collar of the Crankbody.

To create a cylinder:

1. Define the working plane as the XZ plane of the inertia reference.2. While still editing the crank, in the Solid and Markertoolkit, click the Cylindertool.3. Set the Modeling Option toolbar to Point, Point, Radius.4. Click these points and input the radius.

Point1: 10, 0, 170

Point2: 30, 0, 170

Radius: 20

The cylinder should appear as shown next.

5. Right-click the working window, and clickExit to exit the body editing mode of thecrank.


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Moving the Crank Body

To move the crank body:

1. Select the Crank body.2. On the toolbar, click the ObjectControl(Basic) tool.3. Using the Object Control dialog box, move the Crank body70 mm in theX

direction.

4. Exit the Object Control dialog box.5. Change the color of the Crank body.a. Right-click the Crank in the working model window.b. In the Properties dialog box, select the Graphic Property tab.c. Set Colorto gray (second icon in the second row of the color palette).

d. ClickOK.


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Saving Your Model

Take a moment to save the work youve done so far.

To save your model:

From the File menu, clickSave.

Creating the Connecting Rod

Now you will create the connecting rod by creating a cylinder and two ellipsoids and thenuniting them with Boolean operations.

To create the cylinder:

1. In the Body toolkit, click the Cylindertool.2. Set the Modeling Option toolbar to Point, Point, Radius.3. Create the cylinder body:

Point1: -60, 0, 30 Point2: 290, 0, 50 Radius: 7

4. Change the name of the Cylinderto Connecting_Rod. (Tip: To access theProperties dialog box, right-click the cylinder body name, Body1, clickProperties,

and then click the General tab.)

5. Enter Body-Editing mode of the Connecting_Rod, (Tip: In thedatabase window, right-clickConnecting_Rod, and clickEdit.)

Only the connecting rod appears in the working model window.


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6. In the Solid and Markertoolkit, clickEllipsoid and create the ellipsoid geometry: Point: -60, 0, 30

Distance: 13

7. Create another Ellipsoid geometry: Point: 290, 0, 50

Distance: 13

8. Unite all the geometry using the Unite tool in theBoolean toolkit.

The rod should look like the following: (Tip: Set the rendering mode to Shaded. From the

View menu, point to Rendering Mode, and clickShade.)

9. Exit Body-Editing mode. (Tip: Right-click the working model window, and clickExit.)


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Modeling the Slider

To model the Slider body, you will create a base box, an upper center box, and link geometry,and then subtract a sphere from the link to locate the attachment location for the connectingrod.

To create the box:

1. Change the working plane to YZ plane.2. In the Body toolkit, clickBox.3. Set the Modeling Option toolbar to Point, Point, Depth.4. Create the box geometry:

Point1:[ 0, -60, -20]

Point2: [ 0, 60, -40] Depth: 100

The box should appear as shown below. You may need to rotate the model to see

the box (type rin the working model window) and you may need to set therendering mode back to Wireframe with Silhouettes if you changed it earlier to

Shade (from the View menu, point to Rendering Mode, and clickWireframe

with Silhouettes).

5. Change the body name to Slider.To add a box to the Slider body:

1. Enter the Body-Editing Mode ofSlider.2. In the Solid and Markertoolkit, click the Box tool.3. Set the Modeling Option toolbar to Point, Point, Depth.


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4. Create box geometry: Point 1: 0, -30, 20 Point2: 0, 30, -20 Depth: 100

To add link geometry to the Slider body:

1. In the Solid and Markertoolkit, click the Link tool.2. Set the Model Option toolbar to Point, Point, Depth.3. Create the Link1 geometry:

Point 1:0, 0, 50 Point2: 0, 0, -10 Depth: 20

The link should appear as shown next.


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4. Modify the link geometry (Tip: In the Database window, right-click Link1, point toProperty, and then click the Link tab):

First Radius: 20

Second Radius: 25To create ellipsoid geometry:

1. In the Solid and Markertoolkit, click the Ellipsoid tool.2. Create an Ellipsoid geometry:

Point: 0, 0, 50

Distance: 15


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To unite the two geometries:

1. From the Boolean toolkit, click the Unite tool.2. Select the Link1 and Ellipsoid geometries.

The geometry changes from:

To create an ellipsoid and subtract it from the Slider:

1. Define the working plane as the XZ plane.3. In the Solid and Markertoolkit, click the Ellipsoid tool.4. Create an Ellipsoid geometry:

Point: 0, 0, 50

Distance: 15

5. From the toolbar, click the Object Control tool, and move the Ellipsoid2 geometryto 5 mm with respect to +X axis. Close the Object Control tool.

6. From the Boolean toolkit, click the Subtract tool.7. Select the Unite1 and Ellipsoid2 geometries.

To rotate the subtracted geometry:

1. Define the working plane as the YZ plane.2. Select Subtract1.3. From the toolbar, click the Object Control tool, and click the Rotate tab.4. Rotate the Subtract1 geometry 180o about the Z axis as shown below.


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To fillet the edges of the upper box geometry:

1. In the Local toolkit, click the Fillet tool.2. Select the upper Box.

The Fillet Operation dialog box appears.

3. ClickAdd Edge.4. Click the edges that

make up the top andsides of the box, notthe bottom, as shownin the picture to theright. The edgesyou select appear inthe FilletOperation dialogbox, as shownbelow.

5. Change the radius for each edge to 10, as shown inthe Fillet Operation dialog box above.

6. ClickOK.The geometry changes as shown below.


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7. Unite the geometries ofSliderbody. Otherwise the material in the link that intersectswith the volumes of the two boxes would be counted twice in the mass propertycalculation.

8. Exit the Body-Editing Mode of the Sliderbody.To move the Slider body:

1. Change the working plane to the XZ plane.2. Select the Sliderbody.3. Change the color of the Slider:a. In the Database window, right-clickSlider.b. ClickProperty.c. Click the GraphicProperty tab.d. Change the color of the Sliderbody to blue.


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4. From the toolbar, click the Object Control tool, and move the Sliderbody300mm in the +X direction:

Saving Your Model

Before going to the next chapter and adding joints to your model, take a moment to save thework youve done so far.

To save your model:

From the File menu, clickSave.


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Creating Joints

Task Objective

In this chapter, you will create several joints. You will create a:

Revolute joint between the Grounded Bracket and the Crank

Spherical joint between the Crank and the Connecting Rod

Spherical joint between the Connecting Rod and the Slider

Translational joint between the Slider and the Grounded Bracket

You will also define the input motion of the crank.


10 minutes

Chapter

4


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Creating the Revolute Joint

In this section, youll create the revolute joint between the grounded bracket and the crank.

To create the revolute joint:

1. In the Joint toolkit, click the Revolute tool.2. In the Modeling Option toolbar, set the creation

method to Point, Direction.

3. Click two points: Point1 [ -70, 0, 170 ]

Point1 becomes the center point of the joint.

Point2[ -20, 0, 170 ]Point2 defines the rotational axis(z-axis) of

the revolute joint with respect to the point1.

Tip: Modeling Options

When you set the modeling option to Point, Direction, RecurDyn defines the base and actionbodies automatically. The name of the connected bodies can be seen at the right of the cursorposition.

If you want to specify the base body and action body manually, you can specify the bodies bychanging the modeling option to Body, Body, Point, Direction.

Direction Point

Center Point

Base Body

Action BodyCenter Point


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Adjusting the Icon and Marker Size

You are now going to change the icon and marker size to 20 pixels so you can view the modelbetter.

To change the icon and marker size:

1. Display the Icon/Marker dialog box by doing one of the following: In the toolbar, click the Icon Size tool .

From the View menu, clickIcon Size.

The Icon/Marker Size dialog box appears.

2. Set Icon Size and Marker Size to 20.3. ClickOK.

The graphics display changes those shown in the earlier figure to the one shown below.

Creating Two Spherical Joints

Now you will create the two spherical joints that connect between the crank and theconnecting rod and between the connecting rod and the slider

To create spherical joints:

1. In the Joint toolkit, click the Spherical Joint tool.2. Set the Motion Option toolbar to Body, Body, Point.3. Click two bodies and one point:

Body: Crank and Connecting Rod

Point: -60, 0, 30Point becomes the center point of the joint.


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4. In the Joint toolkit, click the Spherical tool.5. Set the Motion Option toolbar to Body, Body, Point.6. Click two bodies and one point:

Body: Connecting Rod and Slider

Point2: 290, 0, 50


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Creating the Translational Joint

Now you will create the translational joint between the slider and the grounded bracket.

To create the translational joint:

1. In the Joint toolkit, click the Translational tool.2. Set the Modeling Option toolbar to Body, Body, Point,

Direction.

3. Click two bodies and two points: Select Bodies: Ground (becomes the base

body for the joint) and Slider (becomes the

action body for the joint)

Point1: 300, 0, -20Point1 becomes center point of the joint.

Point2: 400, 0, -20Point2 becomes the direction point of the joint.It defines the translational axis with respect topoint1.


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Creating a Motion on the Revolute Joint

Now you will define a motion on the revolute joint you just created.

To define a motion:

1. Display the property dialog box ofRevJoint1. (Tip:Right-clickRevJoint1 in the Database window, andclickProperty).

2. Click the Joint tab.3. Check the Include Motion box.

4. ClickMotion.The Motion dialog boxappears. Pull down on thesecond pull-down menuand set the motion type to

Velocity (time).


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5. ClickEL.The Expression List dialog box appears.

For more information on using Exprssion List, see the next Tip.

6. ClickCreate.The Expression dialog boxappears.

7. Enter the following motionexpression in the upper box ofthe Expression dialog box.

2*PI

8. In the Expression dialog box,clickOK.


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The new expression you created appearsin the Expression List dialog box.

9.In the Expression List dialog box,clickOK.

10. In the Motion dialog box, clickOK.11. In the Joint dialog box, clickOK.

Tip: More about the Expression List

Box

The Expression List dialog box stores all expressions used in the model. If you create amotion expression in the Joint dialog box, RecurDyn stores the motion expression in theExpression List dialog box.

You can use an expression in the Expression List dialog box with other entities.


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Performing Analysis

Task Objective

In this chapter, youll run a simulation of the model you just created. The simulation


5 minutes

Chapter

5


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Performing Dynamic/Kinematic AnalysisIn this section, you will run a dynamic/kinematic analysis to view the effect of forces andmotion on the model you just created.

To perform a dynamic/kinematic analysis:

1. In the toolbar, click the combo box next to theSimulate tool, and then clickDynamic/Kinematic.

The Dynamic/Kinematic dialog box appears.

2. Define the end time of the simulation and thenumber of steps:

End Time: 1

Step: 200

Step Multiplier Step Factor: 5

3. ClickSimulate.RecurDyn calculates the motions and forcesacting on the slider crank.

Tip: Meaning of Options in Simulate dialog box

Here is a quick list of the most commonly used options in the Dynamic/Kinematic dialogbox:

End Time: Defines the length of the Simulation Time. Step: Defines the number of animation frames to store throughout the

simulation time.

Plot Multiplier Step Factor: Defines the number of data points that aresaved for plotting. The number of the plot data points that are stored isdefined as:

Step * Plot Multiplier Step Factor


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Working with Animations

Task Objective

In this chapter, you will learn how to animate the motion of the model and how to create anAVI file of the animation for use in presentations. You will also learn how to trace the pathsof points on the moving bodies.


10 minutes

Chapter

6


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About the Animation Toolbar

You can animate your model while modeling or through the RecurDyn/Plot window. Whenyou work with animations in RecurDyn/Plot you can play the animations as you display theplots to more completely analyze the data. The animation toolbar in RecurDyn/Plot is shown

below. Each of its tools are explained in the table below.

The tool Does the following:

Go to the first frame.

Go back one frame.

Play/pause

Fast forward

Go forward one frame

Go to last frame.

Reverse Play/Pause

Fast Reverse Play/Pause

Stop

Record

Animation Scaling

Select camera

Animation controlconfiguration

Playing Animations

In RecurDyn/Plot, in the Animation tool bar, click the Play button.


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Saving the Animation Data as an AVI File

Now you will save the animation you just viewed as an AVI file so you could post it to theWeb or play it in a PowerPoint presentation.

To save an animation as an AVI file:

1. In the Animation toolbar, click the Recordtool.The Create AVI file dialog box appears.

2. Define the size of the image in the AVI file by clicking on the combo box for theMovie Resolution field and selecting600 x 800.

3. ClickSave. The File Save dialog box appears.4. In the File Save dialog box, enter the file name and location for the AVI file.

5. ClickSave.6. In the Create AVI file dialog box, clickCodec.

The Video Compression dialog box appears.You can pick the compression scheme that willbe used to keep your AVI file at a reasonable

size. The image quality, AVI file size andplayback speed can all depend upon the


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compression scheme that you select. If you move the AVI file to another computer,that computer must support the selected compression scheme or the user will not beable to play back the AVI file.

7. Click on the combo box under Compressor and select Microsoft Video 1.8. ClickOK to return to the Create AVI file dialog box.9. ClickClose to exit the Create AVI file dialog box.

Tracing the Paths of Points on the Moving Bodies

In the animation you saw that the motion of the crank, connection rod and slider bodies wassimple but different. Now you will trace out the path of a point on each of these bodies tobetter understand their motion. The point on each body will be defined by a marker. Amarker is a coordinate system. It has an origin and an orientation. You will use some existing

markers to trace some paths.

To trace the path of a point:

1. In the Post menu, click the Marker Tracecommand.The Marker Trace dialog box appears.

2. Click the Add button threetimes to create three lines inthe dialog box.

3. Each line will have a marker button. Click on theMarker button for the first line. The Navigation

Target box will appear in the upper right of theWorking Model Window.


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4. Expand the Crank, Connecting Rod, and SliderBody names in the Database window. Expand theMarkers headings for the Crank, Connecting Rod,and Slider Bodies. The Database Window shouldappear as shown on the right.

5. Select the Marker2 name under the Crank body anddrag it to the Navigation Target Window.

You should see the name Crank.Marker2 appear inthe first row of the Trace Marker column.

6. Click on the Marker button for the second line.7. Select the CM name under the Connecting_Rod

body and drag it to the Navigation Target Window.

You should see the name Connecting_Rod.CM appear in the second row of theTrace Marker column.

8. Click on the Marker button for the third line.9. Select the Marker1 name under the Slider body and drag it to the Navigation Target

Window.

You should see the name Slider.Marker1 appear in the third row of the Trace Markercolumn.

10. Set the Width in all three rows to 3.11. Set the Color in the first row to light grey by clicking on the C button and selecting

the color in the second row and the second column of the palette.

12. Set the Color in the second row to cyan by clicking on the C button and selecting thecyan cell.

13. Set the Color in the third row to red byclicking on the C button and selectingthe red cell.

The Marker Trace dialog box shouldappear as in the figure.

14. ClickOK to close the Marker Trace dialogbox.

15. Play the animation again by clicking onthe play button.

You should see the three traces as shown

in the figure.


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The traces suggest the type of motion that each body is experiencing.

The trace of the slider is the red line, suggesting motion in a single degree offreedom.

The trace of the crank is a circle, suggesting a rotational motion withtranslations in two directions.

The trace of the connecting rod is a slanted circle, suggesting that theconnecting rod is undergoing both a rotational motion and a translationalmotion. The CM marker in the Connecting Rod is translating in all threedegrees of freedom.


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Tip How to use the Animation control configuration

There are several configuration settings for animations that you can set when you selectthe Animation Configuration tool on the Animation toolbar:

Start Frame and End Frame: Defines the start frame and the end frame of ananimation.

Frame Step: Increment frame of an animation.

Repeat: Defines the number of times to replay the animation.

Display Markers during Animation: If you check this option, you can see themarkers during an animation.


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Plotting

Task Objective

In this chapter, you will plot the analysis data that RecurDyn calculated in thedynamic/kinematic simulation you ran in the previous chapter. You will plot the motion ofthe slider body, using RecurDyn/Plot, a powerful post-processing tool, which is built intoRecurDyn. It lets you plot and animate the results of simulations.


5 minutes

Chapter

7


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Creating a Plot

In this section, youll start RecurDyn/Plot and view a plot of the motion of the slider.

To start RecurDyn/Plot and plot the motion of the slider body:

1. In the toolbar, click the Plot Result tool.The Plotting window appears with all the tools and data you need.

2. In the Database window, expand the Bodiesheading, expand the Crank heading

3. Right-click on Pos_TX. Pos_TX is an abbreviationfor Position in Translation in the X direction.4. Select Draw from the pop-up menu that appears.5. Now double-click on Pos_TY and Pos_TZ. You

can see that double-clicking has the same effect asSteps 3 and 4.

The plot should appear as in the figure.

Database window

now contains

output data from

simulations

Tabs for

switching

between plots

and window s

Plotting

window


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Note that the plot gives us the same feedback as the Trace Curve for the Crank body(presented in the previous chapter), which is that the motion of the Crank includedtranslations in two directions. There is no translation in the Z direction.

Plotting in Multiple Panes

In this section, youll learn how to use multiple panes in the Plotting Window to understandyour model behavior more completely.

To switch the Plotting Window to display multiple panes:

1. In the toolbar, click the Show All Panes tool. You should now see four plottingareas within the Plot Window.

2. Set the upper-right pane to be the active pane by clicking on any point within it.3. In the Database window, expand the Connecting_Rod heading under the Bodies

heading

4. Double-click on Pos_TX, then Pos_TY, then Pos_TZ as you did with the previous plot.5. Set the lower-left pane to be the active pane by clicking on any point within it.6. In the Database window, expand the Sliderheading under the Bodies heading


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7.Double-click on

Pos_TX,then

Pos_TY,then

Pos_TZas you did with the previous plot.

The plot should appear as in the figure. The curves in the plot for the slider bodyshow us that the body is moving in one translational degree of freedom. The curves inthe plot for the connecting rod body show us that the body is moving in all threetranslational degree of freedom.

Loading an Animation

In this section, youll load an animation into one of the pane in the Plotting Window in orderto display a coordinated view of output values and the motion of the mechanical system. Note

that an AVI file of the combined plots and animation can be created by following the samesteps that were outlined in the previous chapter.

To load an animation in a pane of the Plotting Window:

1. Set the lower-right pane to be the active pane by clicking on any point within it.2. In the toolbar, click the Load Animation tool.The following alert box appears:


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3. ClickYes and the animation will be loaded in the lower-right pane.4. Change to the XZ plane.5. Type fto fit the model within the pane.6. Type rand drag the cursor in the pane to rotate the model into a better viewing

position. Repeat the fit command as needed.

The Plotting Window should appear to be similar to the figure shown on the cover ofthis tutorial.

7. Play the animation by clicking the Play button.You should see the model animating in the lower-right panes while a vertical lineindicated the location of the current output point in the three plots.

Youre done! Congratulations. By working on through this tutorial, you now understand thebasics of creating a RecurDyn model and studying its motion.


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