Study on the Ductile Fracture of a Surface Crack : (Growth of a Surface Crack and Finite Element Analysis)

Abstract

Ductile fractures of surface cracks were studied experimentally and numerically using two kinds of materials, A 508 C and WT 60. At first, fatigue pre-crack was introduced, and the aspect ratios of the growing fatigue crack were measured. Then the ductile fracture test was carried out and the distributions of SZW and Δa were measured along the crack front for different load levels. It was noticed that Δa is the largest where Φ, the angle from the surface, is nearly 30°, which is considered to be a transition was evaluated by the finite element method, and it is shown that the J value is also largest where Φ is nearly 30°.