2D Rigid to Rigid Contact Simulation

Tutorial Level: Intermediate Learn how to create Curve Entities and Curve Graphics, use macros to create them simultaneously, and setup a 2D rigid curve to curve contact.

This tutorial will guide you through the 2D rigid body contact capabilities in MotionSolve. This can be used when contact occurs in a plane. You will model a roller type cam-follower mechanism using 2D rigid to rigid contact as there are no out-of-plane contact forces that are expected.
Figure 1. Roller type Cam-Follower mechanism


Before you begin, copy the file(s) used in this tutorial to your working directory.

Review the Model

Review the model by running it using MotionSolve.

A partially setup model is available for you in MotionView. Everything except for the 2D contact has been setup.

  1. Launch MotionView.
  2. Open the Model by doing one of the following:
    • On the Standard toolbar, click (Open Model).
    • On the menu bar, click File > Open > Model.
  3. From the Open model dialog, select the file Cam_Follower_2DContact_start.mdl from your working directory and click Open.
    Review the model for its bodies, graphics, markers, joints, and motion. It will look like the image in Figure 2.
    Figure 2.


  4. Review the model.
    The model contains:
    • Cam, Roller and Follower bodies with graphics.
    • A spring damper with an initial Preload between Roller and Ground Body.
    • CurveGraphics on Cam and Roller.
    • A motion on Cam.
    Note: Refer to Higher Pair Constraints tutorial to learn how to create the CurveGraphics.
  5. From the Analyze ribbon, click the Quick Start/Stop Motion Analysis icon .
    From the live run, notice that the FollowerRoller is not in contact with the Cam since there is no contact defined in the model.
  6. Close the Run Status dialog.
    Figure 3. Model animation before contact is set


Set Up 2D Contact

Define a contact between Cam and FollowerRoller.

  1. On the Model ribbon, click on the Contacts icon .
    A guide bar pops-up.
  2. In the drop-down menu, change the Type to 2D Rigid to Rigid.
  3. Click on Body 1 and select the Cam body by clicking its Curve Graphics in the modeling window, as shown in Figure 5.
  4. For Body 2, select the FollowerRoller body.
    The Contact panel should now appear as shown in Figure 4:
    Figure 4. Contact Guide Bar


  5. Click Create to create the contact entity and then click Cancel on the guide bar to exit the context.
  6. Review the contact side of the graphics.
    1. Click to select the Highlight contact side check box.
      Figure 5.


      Note: The arrows indicate the direction of expected contact. For FollowerRoller the direction is from the inside as the contacting side. This needs to be corrected.
    2. In the Entity Editor General tab, click on Graphics to review the graphics involved in the contact definition.
      Figure 6.


    3. Select the Flip Contact Side check box for FollowerRoller.
      Figure 7. Check Flip Contact Side


      Note: The highlighted contact side for both the bodies should now be as shown in Figure 8:
      Figure 8.


    4. Close the Contact Graphics dialog box.
  7. In the Properties tab, retain the default selections.

Save and Run the Model

Save the model and run it using MotionSolve.

  1. From the menu bar, click File > Save As > Model.
    Figure 9. Save Model


  2. In the dialog, browse to your <working directory> and specify the file name as Cam_Follower_2DContact.mdl.
  3. Run the model.
    A 2D curve contact simulation should run faster than an equivalent model using 3D contact where the solver must work harder to determine contact for a 2D tessellated geometry.
    1. Select the analysis Default Analysis in the Model Browser.
    2. Change the Max. Step Size to 0.001.
      Note: A contact model runs more robustly with a tighter step size.
    3. From the Analyze ribbon, click the Quick Start/Stop Motion Analysis icon .
    The simulation should begin with the progress shown in the Run Status dialog while the model animates in the modeling window.

Post-Process the Results

  1. Once the run is complete, click Animate in the Run Status dialog. A HyperView page is added with the result loaded.
    Note: If the Run Status dialog was closed before clicking Animate, the results can be accessed through the Run History icon on the Run ribbon.
  2. Review the contact force.
    1. Select the Vector tool from the ribbon.
    2. In the panel below, set the Results type to Contact Force: Total(v).
    3. Change the graphic settings to transparent using the Mesh Visualization tool in the toolbar.
      Figure 10.


    4. Change Plot, Display and Legends options as per your preference in the Vector panel.
    5. Click Apply. Then click (Start Animation).
      Figure 11.


    The animation shows force on the Cam (Body 1 in the contact definition).

    Save your work to a session file Cam_Follower_2DContact.mvw using File > Session > Save.