A novel measure for the material resistance to ductile fracture propagation under shear-dominated deformation

Abstract Our engineered metallic materials are being designed to be more and more ductile with an increase in strength. Consequently, the failure mode has changed – from brittle to ductile fracture, which leads to a limited applicability of the previously used parameters that quantify the material resistance developed for brittle fracture. This is owing to that a considerable amount of plastic strain is introduced to the fracture process. Shear-dominated ductile fracture failure is commonly observed in many of the structural metals. In the current work, a novel measure Omega Ω is proposed, that fundamentally describes the material’s ability to motivate mass relative motion in response to Mode I shear-dominated fracture propagation. The effects of specimen geometry, fracture tip constraint and deformation modes on Ω were discussed and analysed, which inspired the ideas of normalisation approaches that lead to the development of a dimensionless parameter Normalised Omega Ω ¯ . Accompanying with this concept, our systematically conducted experimental results (DWTT and SENT) indicated, that Ω ¯ is independent to both in-plane and out-plane (specimen thickness) specimen configurations. So that it possesses the characteristic of being an intrinsic material constant for ductile fracture under shear mode.