Newbie question: Stress analysis odd figures?

I have been modelling my first assembly based on a sharp edge tester - a rotating cap on a fixed shaft, and am looking to see what happens to the stresses when I reduce or increase the size of the cap (making it tighter or looser on the shaft).

- See three attached files.

In stress analysis I'm grounding the shaft, and separating the cap and shaft, the applying a 5N moment on the cap.

I would expect to see that as the cap become smaller the stresses rise, and as the cap increases in size, the stresses reduce; to the point where the stresses are negligible as there is zero contact.

I don't see this, and see the cap deform as it rotates rather that simply free float around. So suspect I've put a parameter in wrong somewhere.

I'd also like to model what happens when the cap and shaft are the same dimension, but the coefficient of friction changes, but don't where that's possible. Is it?

Thanks for your patience,

Mark

Finger tester.zip

Your question has been moved to the Inventor section: http://www.cadtutor.net/forum/forumdisplay.php?32-Autodesk-Inventor

I dont have inventor anymore but since there are no answers I wanted to chime in. In fea you typically have to "bond" parts. How have you defined the interface between the two? Usually its something like "non penetrating" plus adding a contact set with your coefficient of friction. Its been about 5 years since I've used inventor so sorry I can't be more help.