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Static bearing model seems to inflate

I'm trying to get some stiffness values of bearings, so as a first test, I made a bearing model for static simulation 101 using contact surface to surface between the parts, but there are some rollers that seems to “inflate” and rotate. But the rotate result shows zero rotation What does this inflate means?

The model is fixed in the out diameter and a force is applied in the center of the inner ring

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Re: Static bearing model seems to inflate

In a geometrical linear analysis the displacements are always calculated from the undeformed reference configuration. If rotation happens, the tangent vector is not updated/rotated, so the part seems to "inflate".


Global CAE Portfolio Development
Accepted by topic author Zoppellari
‎02-03-2017 06:20 AM

Re: Static bearing model seems to inflate

Okay, my last entry to this was sent unintentionally when my browser crashed ...


Again: In a geometric linear analysis, the tangent displacement vector caused by a rotation is not updated, so the vector does not rotate itself. By that, the structure indeed "inflates".


I attach a scetch where a circle rotates - and the red arrows are marking the displacements caused by the rotation. Since the direction of the red erros does not change, the new structure (dotted in red) is "inflated". 


Clearly, large rotations must be analysed with a geometrically nonlinear analysis. Quite likely that in your analysis the rollers rotate unintentionally - try to fix rotation with soft springs. 

Global CAE Portfolio Development