c) A brittle ceramic rod contains a semi-elliptical opening, crossing the thickness of the part. Upper material has resistance maximum tensile strength of 600 MPa, a Young's modulus of 400 GPa, and a toughness 5.50 MPa.m7/2, A force F of 200 kN is applied along the length of the rod. The rod has an S section of 10 cm? (area of the plane normal to the force vector). The geometric correction factor (alpha) of the defect is worth 1.12.

Calculate the minimum value of the depth of the defect to satisfy the energy criterion of Griffith Orowan