In ball and socket joint analysis with friction coefficient as 0.3, I got this warning

In my project while doing fatigue analysis of ball and socket joint for hip implant,

I got this warning

One or more contact pairs are detected with a friction value greater than 0.2. If convergence problems arise, switching to an unsymmetrical Newton Raphson option may aid in convergence.

what should I do now?


  • bsistabsista Posts: 99Member

    High friction (typically coeff. of friction higher than 0.2) between surfaces can make the stiffness matrix unsymmetric. Sometimes, such cases may face convergence issues in which case using an unsymmetric Newton-Rapshon solver is helpful. In your case, if you did not run into any convergence issues and have a solution (all green check marks on model tree), then you may ignore this message. If you run into convergence issues, then changing the Newton-Raphson option (Analysis Settings --> Nonlinear Controls --> Newton-Raphson Options) to Unsymmetric could be helpful.

  • Mukka_SrikanthMukka_Srikanth Posts: 2Member

    Yeah it was helpful...thank you for detail answer

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