NonlinearPeric.md

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

$$ \dot\gamma(\sigma,\sigma_y)=\left{\begin{array}{ll}\dfrac{1}{\mu}\left[\dfrac{q(\sigma)}{\sigma_y}-1\right] ^{1/\epsilon},&\Phi\ge0,\0,&\Phi<0.\end{array}\right. $$

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