Simulating Bearings

[bengineer04]

Hello,
I've been struggling with trying to simulate angular bearings in Mechanica (WF2). I'm trying to use spring idealizations to replace the bearings and I'm able to simulate the axial direction perfectly, but the radial direction never works. I get everything from incredible displacements (on the order of thousands of inches) to displacements off by about a factor of ten from what I'm expecting. I've spent nearly four days playing with different orientations, number of springs... and nothing.
Does anyone have a way to simulate bearings?

 

[seymours2571]

Bengineer04,

You can simulate bearings using solid elements in conjunction with a cylindrical coordinate system. You can only create a cylindrical csys in Mechanica (as opposed to Pro/E).

When you set the displacement boundary conditions on the outer surface of your solid model bearing make sure to change the referenced coordinate system to the newly created cylindrical coordinate system. When you do you will now have new selections for radial, tangential, and axial displacement constraints.

If you are trying to simulate bearings using spring elements then the best spring types to use would be ground springs. Here you can set both translational and torsional stiffness constants. However, I believe the solid model approach mentioned above would be the best option.

Hope this helps,

Steve