<FLOW> modified_visco#

Description#

This flow law is a Norton type viscoplastic rate, using a strain hardening or softening viscocity term.

Let the following terms be defined:

(399)#\[d_1 = \left<\frac{f}{K}\right>^n \hskip2cm K = K_0+Q(1-e^{-b v})\]

With which the flow law is written:

(400)#\[\dot{\lambda} = d_1 \exp\left[\alpha d_1 \frac{f}{K}\right]\]

The flow law accepts coefficients K0, Q, b, n and alpha.

Note

There is another version of this flow called norton_hardening which reduces to:

(401)#\[\dot{\lambda} = \left<\frac{f}{K_0+K(1-e^{-b v})}\right>^n\]