Plasticity

Hi all,

      I doing modelling on soft clay behaviour which exhibit softening behaviour during constant strain loading. Here i followed a non-associated flow rule for better prediction of dilation . For the case of non-associated flow rule yield function and plastic potential function should not same i clear in that , my doubt is that we can use two different surface for yield and plastic potential function (eg: linear surface as yield surface and elliptical surface as plastic potential )? 

Hello,

I am trying to derive/find an analytical expression
for the torsion of a round bar made of an heterogeneous material. But I just do
not seem to find any solution available in the literature other than for a
homogeneous material, which can be find in any theory of plasticity book (e.g.
Theory of Plasticity, 3rd Ed., J. Chakarabarty, pp. 132-136).

Dear all,

Is there any one of you know a material model which can reflect the orthotropic , hysteresis, and load ratio dependence behaviors? 

Every helps would be highly appreciated.

Kindest regards,

Ken

Dear Colleagues,