Interference fit in an axis-symetric FEA Model

[merlinmer]

I have a common analysis problem of evaluating interference fits utilizing an axis-symetric FEA model. I would like to perform this analysis in Nastran but I don't know if it is possible with Axis symetric elements. I heard Anysis does this type of analysis quickly and easily. Any suggestions?

Thanks

 

[corus]

You could do this in different ways. In Abaqus you can use contact between two surfaces and specify an interference fit or generally specify two temperature regions which would give differential thermal expansion and hence the interference fit. This is regardless of whether or not the elements are axi-symmetric.

corus

 

[johnhors]

As Nastran doesn't have a contact facility, you will have to use Corus's second suggestion of using differential thermal expansion for the different parts of your model. The parts can be joined using (stiff!) spring elements. You have to be careful in first calculating what temperature and coefficient of expansion you require for each part to obtain the correct interference fit. In fact this method can be run as a simple linear analysis, whereas the Abaqus contact approach whilst being simpler in setting up is a non-linear analysis and can (sometimes) fail to converge correctly.