Influence of constraint on the micromechanics of fracture of AL2024

A clear understanding of the fracture behaviour of materials is of great importance in assessing the safety of cracked components. Despite this fact, there is considerable uncertainty in the effect of plastic constraint in the fracture of metallic materials. It is rare that good fracture predictions can be obtained, particularly in the case of combined in and out-ofplane constraint. Hence, the purpose of this paper is to explore this combined effect in one of the most frequently used materials in the aerospace industry: Aluminium alloy 2024. To this end, a numerical simulation is performed which includes the interaction between voids which form in the early stages of the loading and a pre-existing crack. It is shown that good predictions can be obtained for different levels of in and out-of-plane constraint using a local fracture criterion. This is confirmed by comparing the finite element predictions and the results of experimental studies. KEWORDS In-plane constraint, out-of-plane constraint, stress triaxiality factor.