| a (mm) | θ | Theoretical θcr (rad) | 2D FEM θcr (rad) | XFEM θcr (rad) | 2D FEM Error (%) | XFEM Error (%) |
| 2.5 | 25o | −0.67544 | −0.6523 | −0.68545 | −3.424 | 1.481 |
| 2.5 | 55o | −1.0107 | −0.99985 | −1.01615 | −1.0707 | 0.539 |
| 2.5 | 60o | −1.04695 | −1.03875 | −1.0516 | −0.7832 | 0.446 |
| 2.5 | 80o | −1.17265 | −1.1642 | −1.17415 | −0.7205 | 0.128 |