<CRITERION> hill

Description

The Hill criterion allows modeling of anisotropic behavior in the criterion and flow directions.

(351)\[f_{cr} = \left[ \frac{3}{2}\hat{\ten \sigma}:\tenf M_{hill}:\hat{\ten \sigma}\right]^{1/2} - R\]

where \(\bf M_{hill}\) is a diagonal matrix of independent coefficients. These coefficients are named hill1 \(\dots\) hillN with N being 4 for two dimensional problems, and 6 for three dimensional. There is no problem giving the complete 6 coefficients in a 2D problem however.

Example

**potential gen_evp ev
  *flow norton
   n  4.0
   K  500.
  *criterion hill
   hill1 1.
   hill2 2.
   hill3 3.
   hill4 1.2
   hill5 1.7
   hill6 0.8
...