0 Replies Latest reply on Jan 8, 2013 4:32 AM by Mikael Martinsson

    Von Mises plasticity - Tangent modulus

    Mikael Martinsson

      Hi.

      We lack the Premium, full non linear possibilities, but have access to drop test in Simulation.

      There I can define a bilinear material model and add a tangent modulus for plasticity - Von Mises.

      I was under the impression that elastic modulus were valid up to yield strength before the tangent modulus comes into play and material stiffness decreases..

       

      When I did a drop test on a simple geometry with linear elastic isotropic material and then duplicated it and selected plasticity Von Mises with a tangent modulus 1/20 of modulus of elasticity the maximum stress was lower compared to the linear elastic as expected.

       

      But the maximum stress in the second example was even below yield?

      My falsely assumption made me think that the results between the two studies would be similar up to yield since all other parameters where similar (drop height, type of "floor", large displacement" e.tc.)

       

      Please help me understand how this works.