3 Replies Latest reply on Feb 4, 2015 2:04 PM by Jared Conway

    Nonlinear material -> convergence tolerance

    Mikael Martinsson

      I have a question regarding convergence tolerance in non linear analysis. Described in an example below:

       

      If I try a nonlinear Von Mises Plasticity material model and my first point in the SS table is 0,0027 strain at 136 MPa.

      I then do a simple rectangular beam say 10x10 mm extruded 30 mm or so.

       

      The beam is restraind correctly for a pure tensile load, so "roller/slider" on the surface (Z), 2 points (Y) and 1 Point (X) so no singularities occur due to poissons effect.

       

      A pressure of 136 MPa is added to the free end in pure tensile direction.

      Solver is "Direct Sparse" and mesh size more than 3 elements thru the thickness of the part.

       

      The reported stress is 136,1 for all colors (sparse solver) but the reported strain is only 0,00235.

      Is this a result of the convergence tolerance settings in the solver, and if so, where can i modify this value to get closer?

      If not, why don't the result follow my stress strain curve? I need to go up to 142 MPa to meet 0,0027 strain

       

      Thanks in advance.