A damage equivalence method to correlate the geometry effects on elastic plastic fracture toughness

Abstract

The classical elastic plastic fracture mechanics theory [1,2] assumes that a single parameter, J-integral [3] or crack tip open displacement ~<, uniquely defines the conditions near the tip of a crack; the critical J-value or 8,-value at fracture initiation is assumed to be a material constant [4,5]. In fact, the FEM analyses for different specimens showed (e.g. [6]) the stress fields near a crack tip for specimens used in the laboratory are different from that of the HRR field, on the other hand, some experimental studies [7,8] have demonstrated a significant increase in the apparent elastic plastic fracture toughness.