NonlinearPeric

Viscoplasticity

Similar to the classic rate independent J2 plasticity, the NonlinearPeric class defines a J2 plasticity incorporates viscoplatisicity using Peric's model, that is

$$\dot{\gamma }(\sigma ,{\sigma }_y)=\{\begin{array}{ll}{\displaystyle \frac{1}{\mu }}{[{\displaystyle \frac{q(\sigma )}{{\sigma }_y}}-1]}^{1/ϵ},& \mathrm{\Phi }\ge 0,\\ 0,& \mathrm{\Phi }<0.\end{array}$$

In which, $\mu$ is viscosity related parameter, $ϵ$ is rate sensitivity, larger $ϵ$ represents response to be more sensitive to rate, $q(\sigma )=\sqrt{{\displaystyle \frac{3}{2}}\eta :\eta }$ as before is the effective von Mises stress.