Question

A center-cracked panel with an initial crack length of 0.010 mm is subjected to a tensile cyclic stress between 25 and 125 MPa for 350000 cycles. The panel is then subjected to a tensile cycle stress between 0 and 250 MPa. How many of the larger stress amplitude cycles can be sustained before failure? The material has a fracture toughness of 25 MPa?m and material constants n = 3.1 and C = 1.8 x 10^-10 for these units.

Answer 1