EFFECTS OF CRACK FRONT CURVATURE ON J AND CTOD DETERMINATION IN FRACTURE TOUGHNESS SPECIMENS BY FEA

摘要

This paper investigates the effect of crack curvature on a single edge notched bend (SENB) specimen using finite element analysis (FEA). The variations of J and CTOD were studied through the thickness of the specimen for different levels of crack curvature. Five different curved crack fronts were considered, with the same weighted average crack length based on BS 7448. The levels of curvature varied from a straight crack front to a maximum deviation of 25% from the average crack length. The findings can be used to recommend more comprehensive crack curvature qualification checks for SENB tests and potentially provide improved estimates of fracture toughness when curvature is greater than allowed by the standard.