Fracture toughness and failure limits in sheet metal forming

This paper proposes a link between plastic flow, void coalescence and growth, ductile damage, crack opening modes and fracture toughness in sheet metal forming. This new integrated view is based on an analytical framework that allows estimating the location of the fracture loci in the principal strain space directly from material stress–strain response and from fracture toughness and thickness at fracture obtained from double-notched test specimens loaded in tension and plane torsion (in-plane shear). Experiments in AA1050-H111 aluminium sheets with 1 mm thickness give support to the proposed analytical framework.