Main Question or Discussion Point
I am trying to evaluate SIF for 3D plate using ansys APDL. Please share tutorial/notes if available.
Sure...I did a little internet searching and found a couple of results, are you having trouble finding the information you need? We need you to actively contribute to this conversation if you're going to get anything out of it. ANSYS also has excellent documentation, what have you found in their help files?
You might try this paper, which seems to cover your topic: Three Dimensional Static and Dynamic Stress Intensity Factor Computations Using ANSYSSure...
I have seen many tutorials for SIF evaluation. But all were for 2D plate. I am trying for 3D plate so that I can get variation of SIF along thickness.