Contact within a submodel

[AmyLovisa]

Hi Everyone,

I am using the submodelling technique to look at stress concentration around a fastener hole in a thin steel sheet. The surface is also then in contact with a rubber washer which compresses the region around the fastener hole. I have successfully applied the submodelling technique for a basic version of my problem, which was a challenge since you need the washer to compress at the same moment in both the submodel and global model. I have now expanded the problem so the steel sheet undergoes some initial preloading before being loaded by the washer. The global and submodel results match for the preloading step but when I apply contact with the washer, the two contact at differing times. Looking closely, the offset of the contact surfaces in the global model is half the shell thickness as expected, but in the submodel the offset is only a quarter of the original shell thickness. I have double checked the contact definition and the shell description between the global and submodel input files, they all match up. Could the shell possibly have thinned during preloading in the submodel analysis?

I have a few ways of working around this issue but would rather know the circumstances of this new issue.

Thank you so much in advance!

 

[Mustaine3]

Are you using Explicit and general contact?
Sometimes Abaqus decreases the shell thickness to prevent self contact/penetration when the mesh is to fine compared to the shell thickness.
Users Manual 36.4.5 Contact controls for general contact in Abaqus/Explicit

 

[AmyLovisa]

Hi Mustaine3

It is general contact in an Explicit analysis! I will look into the controls now. Thank you so much for the advice!