3 Replies Latest reply on Sep 8, 2006 10:32 AM by

    Different behaviours in tension and compression: can Non-Linear treat them?

      Hi Francesco, as I stated in COSMOS Companion webcast, using VMS for fatigue was contradictory to my prior work that I never tried that option. Enough people asked that I plan to explore it and update my notes on it.

      Are you subscribed to the COSMOS Companion thread above in the News group? I'll probably post any updates there.

      By the way, I've done a number of grey iron studies in my former life where I could have used an asymetric nonlinear elastic material model. If you get a chance to try it, let me know what you think.

      -- Vince

      Vince
        • Different behaviours in tension and compression: can Non-Linear treat them?
          I have no actual studies of this kind yet.
          I was just wondering about it.
          This thought came from a different subject, but there is no real connection.

          After the latest Companion Seminar,
          I am doing some test with the fatigue solver, and I was looking for a behaviour, i.e.:
          Von Mises values don't tell compression from tension, so VM can roughly predict fatigue zones just when the load factor is -1 and VM-high zones are alternatively loaded in tension and compression.
          If the factor is 0, I expect compression-predominant high-VM zones to be less affected by fatigue than tension-predominant.
          Am I right or this is not considered in our solver?
          Francesco
          • Different behaviours in tension and compression: can Non-Linear treat them?
            Yes, an asymmetric SS curve can be entered into CW Nonlinear. If the curve is defined completely in Q1, CW assumes symmetry. However, it will recognize a different compressive response if you key it in.

            What material are you exploring?

            Vince
            • Different behaviours in tension and compression: can Non-Linear treat them?
              I was wondering if in a non-linear study Cosmos can analyse a stress-strain curve that is not symmetric around the origin, i.e. the material has a different curve in compression and in tension.
              Of course I mean a difference that can start in the very first elastic domain, not something that could be simply judged with a Mohr-Coulomb criterium...
              I know some cast irons show such a property, even if this is more important in dynamic problems.
              Has anyone encountered this theme, so far?