Power Law Model

The power law model is equivalent to the “strain hardening” form. Use the power law model when the value of the material parameter $A$ is very small $(A \leq 10^{- 27})$ . In this case, the equivalent power law model is obtained by setting $q_{0} = {\dot{ε}}_{0}^{\frac{m + 1}{n}} A^{- \frac{1}{n}}$ , keeping the parameters $m$ and $n$ unchanged, and setting ${\overset{\cdot}{ε}}_{0}$ to an arbitrary value greater than zero. Typically, ${\overset{\cdot}{ε}}_{0}$ is set to one. The power law model rewrites the law in such a way that the typical parameter values do not cause numerical difficulties. In addition, the units of all of the parameters are physical, which makes unit conversion easier if required.