Hello, everybody.
I have been developing anisotropic damage criterion using the UDMGINI subroutine. I realized that the normal direction to the fracture line should be defined in FNORMAL array. However, I cannot understand how the ABAQUS decides in which direction the crack must grow. For example, suppose the tip of pre-crack reaches the middle point of the bottom boundary of an element and the normal vector is (0,1) or (0,-1), How does Abaqus determine if the crack expands to right or left.
another question is that is there any way to restrict the crack growth in a predefined direction? (I mean for instance, to positive Y-direction in a way that crack does not expand downward)