The X axis must be parallel to the crack face (perpendicular to the crack front in 3D models) and the Y axis perpendicular to the crack face (as shown in Figure 1.5: Crack Tip and Crack Front).

The coordinate system must be the active model coordinate system (CSYS) and results coordinate system (RSYS) when KCALC executes. (See the LOCAL (or CLOCAL, CS, CSKP, etc. commands.)