Advice for contact elements in Abaqus 2

[Jlog50]

Hello all,

I am currently modelling 3D hertz contact problem in Abaqus. The manual does not give much advice on contact element types for contact problems.

The contact is finite sliding (likely to be more than small sliding), penalty tangential behavious (COF = 0.1), "Hard" normal contact.

The geometry is very simular to ball in socket where i have found hex elements are efficient (i.e. by using the C3D10M tet elments suggested by Abaqus for complex geometrical contact problems I needs almost 5 times the number of the elements for the same seeding number.

Can anyone suggestion any suitable hex elements for this type of problem? As opting for C3D8R vs C3D8I can give a massive difference on the result. Also, some element types show a very un smooth stress profile on the surfaces (dispite being a smooth ball in socket joint simulation).

Thanks.

 

[portliner]

Recommend full integration C3D20 (with automatically generated midface node on face in contact). Full integration is recommended in regions with high stress gradients.

/Stig

 

[Jlog50]

Thanks for your input Stig. I have heard that linear elements are better suited for contact problems? Do you have any thoughts on this?

Thanks

 

[MechIrl]

Yes, its generally best to stick with fully integrated linear elements and avoid tets for contact. Stick with C3D8s.

 

[portliner]

I never use linear elements in any analysis. They are too stiff in bending(except for C3D8I but they are very sensitive to distortion). A large number of linear elements is needed if closely modelling curved geometry.

/Stig