next up previous contents
Next: Viscosity Up: Material deformation and flow Previous: Viscoelasticity   Contents

Viscoplasticity

Viscoplasticity is a model for rate-dependent plasticity. Rate dependent plasticity is important for (high-speed) transient plasticity calculations. It should be used in combination with a plasticity law. Viscoplasticity influences the stresses via the plastic strains.


\begin{displaymath}
\dot{{\epsilon_{kl}}} ^{\rm plas} =
\eta ( \frac{f}{f^{\rm ...
... ^ p \;\;
\frac{\partial f^{\rm flow}}{\partial \sigma_{kl}}
\end{displaymath}

where $\eta$ (fluidity constant), $f^{\rm ref}$ (reference value for yield function, e.g. the yield stress for Von-Mises plasticity) and p (power) are user specified parameters for the group_materi_plasti_visco model.



root
1998-11-16