Conditions for shear localization in the ductile fracture of void-containing materials

摘要: This paper investigates the possibility that ductile fracture occurs by McClintock-Berg mechanism of localization deformation within a narrow shear band, owing to progressive softening material increasing porosity due void growth. The ductility predicted for macroscopically homogeneous sample voided is shown be unrealistically large and hence an initial inhomogeneity properties considered, in sense analysis Marciniak Kuczynski related problem local necking sheet metals. General conditions bifurcation with (imperfection), concentrating allow it, are derived. imperfection taken form void-containing, thin slice assumed have volume fraction slightly larger than outside imperfection. Elastic-plastic constitutive rate relations void-containing materials proposed Gurson adopted bifurcation. critical analyzed numerically discuss sensitivity imperfection, consideration implications theory fracture. results suggest existence makes it possible occur at reasonable strain, predictions from this seem broadly consistent reported experimental observations.