Some confusion in Craig chang contact flexible body in Motionview

Jin1

In Motionview, CBC's flexible body can be set for contact calculations with the flexible body. Now I see two settings below (including contact models at rigid nodes, as shown in my screenshot), but I have looked at the help documentation and don't quite understand how to set them up. Assuming I have a bearing, how should a roller in the bearing be set with CBC flexible body. If a swing arm (as shown in Figure 2, the red box represents the contact area) needs to make contact with a portion of the grid, how should it be set up.

Christopher_Fadanelli

Hi @Jin1 ,

The first step in setting up flexbody contact is to generate a flexbody using any CMS method (CB, CC, or CBG). Select the flexbody that will be used for contact. In the Entity Editor, go to Contact Prediction and enable Generate Contact Loadsets. Leave Maximum Loadsets set to 0 (this allows the maximum number of loadsets to be generated). Then, define the location where the Loadset File (LSF) will be saved.

Next, run an initial simulation with contact enabled. Once that simulation is complete, open the dialog with the corresponding .fem file and save the resulting .h3d file under a new name (e.g., flexbody_enhanced.h3d). Enable CCC.

If a region of an interface node that has been rigidified using an RBE2 element must be included in the contact, the rigid connection of that interface node needs to be released. In such cases, specify these nodes under Include Contact. If this is not required, you only need to input the Loadset File (LSF). Then, run Flexprep.

After Flexprep has completed, return to your MotionView model and replace the existing flexbody with the enhanced one. It’s recommended to disable Contact Prediction at this point to prevent generating another LSF file. Finally, rerun the simulation.

There is a public example that shows how to enhance a flexbody: Consumer Electronics Drop Testing. Part 3: Euler Angle Setup

References:

https://help.altair.com/hwdesktop/hwx/topics/motionview/flex_contact_r.htm

https://help.altair.com/hwdesktop/hwx/topics/motionview/optistruct_flexbody_generation.htm

Hope this helps!

Christopher Fadanelli