BilinearPeric
Bilinear Peric Viscous Plasticity Model
Theory
The rate of plasticity multiplier is defined as
\[
\dot{\gamma}=\dfrac{1}{\mu}\left(\dfrac{q}{\sigma_y}-1\right)^{\dfrac{1}{\epsilon}}
\]
where \(\epsilon\) and \(\mu\) are two material constants, \(\sigma_y\) is the initial yield stress, \(q=\sqrt{\dfrac{3}{2}s:s}=\sqrt{3J_2}\) is the von Mises stress.
The yielding surface is identical to that of the von Mises model.