Numerical model of brittle crack propagation considering fracture surface energy on high tensile strength steel

- Proposal of a numerical model of brittle crack propagation (report 1) -

Abstract

Brittle fracture propagation issue has been focused from the viewpoint of margin of safety in some steel structures which require high fracture safety. In this study, Importance of absorption of fracture surface energy(G_c) during cleavage crack propagation in poly-crystal material is pointed out. Model experiment at -196 deg.C by Compact Crack Arrest specimen and FEM analyses based on the local stress criterion method were performed using YP32 steel and its material constant considering G_c concept. FEM analyses where the critical stress, σ_f is set to 2150MPa which is the same value as its critical stress for crack initiation and G_c is set to be 500J/m² show excellent agreement with experiment in their crack propagation velocity and arrested location.