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Appropriate Contact Gaps

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TomFin

Mechanical
Jun 21, 2006
79
Simple Assy consists of a shaft, collar and a rollpin that keeps the collar rotating at the same speed as the shaft as well as prevents the collar from transposing along the axis of the shaft. Therefore there is a hole drilled through the collar and shaft that the rollpin fits into. Id like to perform an accurate FEA analysis. The scenario I'd like to simulate is this: the components are assembled as described above. The shaft is fixed and a torque is applied to the collar that wants to break or shear the pin. Im new to contact gaps and would appreciate suggestions/confirmations as to the appropriate contact gaps for this scenario.

Thus far
Shaft OD / Collar ID --> Contact/Gaps Option: Free



 
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I'm not an extremely experienced COSMOS user, but from a recent discussion on this with my SW VAR, in this situation I would use "No Interference" in the Shaft OD/Collar ID, the Pin OD/Collar Cross Hole ID, and the Pin OD/Shaft Cross Hole ID.

Hope this helps.
 
Thanks Chattaggie,
I tried this method before my original post and was getting results that were not consistent with my expectations. Perhaps my expectations are intuitive as opposed to the results Im getting. The stress spectrograph leads me to believe COSMOS is interpreting my analyis as a complete rigid body. Because of this I simplified the model by removing the collar and just applying a torque to the pin.
By the way, does anyone have any helpful resources for the appropriate use of various restraints and contact gaps. I feel this is the main cause of erroneous FEA ~ garbage in garbage out.

Thankyou,
Tom
 
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