Discovery Import

Discovery Import

Multilinear Isotropic Hardening

    • albin.linderstam


      I want to perform a analysis of a component using Plasticity.

      I’ve have a stress-strain curve from MMPDS, see attached image. According to MMPDS, the curve is a Engineering Stress-Strain.

      We have used similar analysis a long time ago, but that was in Ansys R15.0. However, in that version, the Total Strain was entered instead of Plastic Strain, see attached image.

      I’ve some questions regarding this; especially about preparding the correct table to input in Ansys:

      1. Ramberg-Osgood Equation: I have E, Fty and n (see attached image), so I simply try to create a lot of stress-strain values from this equation using this parameters, but I don’t get the correct values. Is the method correct? In the second attached image, I show my values from this equation and parameters. According to the graph, 169ksi should give ~0.011, but I get ~0.085, so I’m way off. Cannot find out why.

      2. According to [

      " rel="nofollow noopener noreferrer" target="_blank">https://
      " rel="nofollow noopener noreferrer" target="_blank">
      ], True Stress-Strain is required; should I convert from Engineering to True stress-strain using the equations in attached image and then subtract the elastic strain (s/E) to only get the plastic strain?

      3. According to [

" rel="nofollow noopener noreferrer" target="_blank">
], the first point should be (0, yield strength), but how should I then include 0.2% plastic strain at yield point? There is a parameter called Offset, but I cannot modify the values. Should this parameter be used somehow? Or should I use (0, yield strength) even though this value is 0.002? 

Regards, Albin

  • Subashni Ravichandran
    Ansys Employee

    Albin Linderstam

    This Forum is meant for support on Ansys Discovery products only. For queries related to other Ansys products please post them on Ansys Customer Portal

    • albin.linderstam

      Subashni Oh sorry! I'm a bit confused of all forum updates lately. 

  • Viewing 1 reply thread
    • You must be logged in to reply to this topic.