using FELFM

Hi All

 Currently I am running FE modelling using linear elastic fracture mechanics approach to estimate crack growth propagation in a web plate of box girder in an existing bridge deck. The FE model includes 3D solid element. The crack growth direction is expected to follow in a plan perpendicular to the maximum principal stress.

 As I know there are many methods can be used to estimate the direction of crack during propagation. My question is about the maximum tangential stress criterion method.