I have applied Shrink Fit/Sliding between the bore of a hub and the OD of a shaft. I have included 0.0045" interference between the surfaces and a 1.0 friction factor. The results show the surfaces move relative to each other but there is some sort of local loading between two pairs of nodes that appear to be tugging on each other. I have tried both part-to-part settings as well as surface-to-surface settings. On previous versions of this model, I obtained results that did not exhibit this sort of erroneous action. This is causing an inappropriate extreme level of stress. What would explain this sort of behavior?
Hi,
I have a few questions about your image.
I thought that the only type of contact that can handle different meshes on the "matching" surfaces is bonded contact, and only when "smart bonding" is activated. This can cause "hot spots" in the stress results.
here is a PDF file of my message with th images included
Hi Jay,
It does look like there is some mismatched mesh. To clarify one statement I made before, there will be contact between nodes that are matched on the two parts (same physical coordinate) but no contact where the mesh is not matched. Obviously, this later situation does not match reality. I do not have a suggestion about the matching other than trying your suggestion of an all-tet mesh. (You may even want to redo one of the previous models with all-tet and compare the results.)
One solution that may help the hot spots is to right-click on the contact listing in the browser and choose "Settings". Change the "Surface contact direction" to "Normal to the first part/surface" or to the second part/surface. I think the hot spots are due to the contact elements being crooked where the mesh transitions from matched to unmatched. Of course, these hot spots are a secondary concern -- the first concern is getting the mesh to match.
When ever working with surface contact, you should always check the "Results Contours > Other Results > Element Forces > Axial Forces". This will show what the contact force is, but more importantly, it will show where there are no contact elements (because there will be no contour in that location).