Unified CDM model and local criterion for ductile fracture-II. Ductile fracture local criterion based on the CDM model

A unified local criterion for ductile fracture is proposed on the basis of the continuum damage mechanics (CDM) model given by the author in Part I [Engng Fracture Mech. (submitted)], in which the stress, strain and damage history are included. The new ductile fracture parameter W_DC has obvious physical meaning and can be determined by a macroscopic method, which is experimentally verified as a material constant independent of stress states. Comparisons of the present criterion with others are given, which show some advantages of the present criterion over others. The relationship between local parameter W_DC and the well known global parameter J_C is also established.