Due to the cuved crack front, I don't konw how to defeine the crack propagation direction. Anyone konws how to define a curved crack in ansys workbench at the interface of two materials?
crack propagation direction is not super critical for a linear static calculation of SIFs, you can test this for yourself by putting a circular defect completely within a solid body, the SIFs will be calculated correctly along the entirety of the crackfront, regardless of the orientation of you coordinate system (top and bottom must still be correctly oriented). However, depending on your analysis, you may not simply be interested in SIFs.
The presence of two materials at the crack front is problematic, and you will get a warning or error from MAPDL regarding the two material models, if you are calculating SIFs (or J-Integral etc...).
Is this a case where you should be using delamination/contact debonding?
Ansys customers with active commercial software licenses can access the
customer portal and submit support questions. You will need your active account number to register.