Axisymmetric non-linear thread tube with contact and plastic deformation

General Questions
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I tried here to perform a contact analysis between two threaded tubes with plastic deformation in an axisymmetric setup. I have the impression that the result is not physically correct—the Von Mises stresses do not seem accurate in either part. It’s as if the lower piece is not experiencing the force flow. Could my contact definitions be incorrect? Is there any specific consideration for performing axisymmetric contact analyses? I’ve also attached my simulation for reference. (SwissTransfer - Send large files securely and free of charge)

2
  1. Why are you using node-to-surface contact ? Surface-to-surface is usually better. Often it’s also necessary to reduce the default contact stiffness to improve convergence, but watch out for penetrations.
  2. I’ve noticed that you didn’t include friction.
  3. CAX4 elements are internally expanded to C3D8. It might be better to use the reduced integration version and refine the mesh as needed.
  4. Try adjusting the color legend limits to better see the stress distribution away from the largest peaks.
  5. If you need a reference solution, you can try with a similar model from Abaqus documentation (input decks provided there can be easily converted for use in CalculiX): http://130.149.89.49:2080/v2016/books/exa/default.htm?startat=ch01s01aex20.html
  6. Check CPRESS to see where contact is established, but keep in mind that CPRESS is displayed only on the slave surface.
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Thanks for the tips. I modified my mesh, add some friction. I think in this kind of case we have to go to watch the constrain in Y direction to see the force flow passing through the two pieces. If you go on Von-Mises, the constrain in radial direction is biger as the axial (y) constrain and is hided.

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