Learning Forum

[AbelBerhanemeskel]

Hello Everyone,nI was Trying to model a frame assemblage under Cyclic Loading. I have a material parameters for the Chaboche Kinematic Hardening model and the parameters for the nonlinear isotropic hardening Exponential law. My Question is since Ansys Only Has the Voce and Power law nonlinear isotropic hardening model can I use the Voce law with the linear coefficient equal to zero (since the the Voce law and the exponential law formulas only differ by the linear coefficient in the Voce law)? What I am basically asking is if Ansys will have a numerical problem while solving if I make the linear coefficient zero? I only have the parameters I specified above I can't curve fit anything. nExponential Law = sY=s0+R8?(1-e-b?e?p?l)nVoce Law = sY=s0+R0*?e?p?l+R8?(1-e-b?e?p?l)nAny help or Suggestion will be very helpful.nThanksnn

[John Doyle]

I am assuming, by 'linear term' in Voce model, you are referring to Ro. Yes I believe you are correct. ISection 4.4.2.2.3.2of Material Reference Manual, we describe Voce model as ... similar to bilinear isotropic hardening, with an exponential saturation hardening term added to the linear term. So in looking at the two expressions, Voce reduces to the exponential expression with Ro (the linear term) set to zero. It is hard to say if ANSYS will have any convergence problems with this. It depends on the application.

[AbelBerhanemeskel]

Thanks jjdoyle for the reply, I have tried it and it works without any problem.n