MIXED-MODE FRACTURE-TOUGHNESS OF ENGINEERING MATERIALS

The effect of mired mode lending on the fracture roughness of engineer ing materials is rationalized in terms of the operative fracture mecha nism as well as the deformation field ahead of the crack lip. It was f ound that mixed mode fracture is of utmost importance in materials whi ch fail by stable ductile fracture caused by second phase particles, s ince in such materials there is a significant reduction in fracture to ughness on mixed-mode lending. An autocatalytic shear localization-voi d formation mechanistic model was found to qualitatively explain the m ixed mode fracture behavior in such materials.