A continuum model for void nucleation by inclusion debonding. (English) Zbl 0626.73010

Needleman, A.

J. Appl. Mech. 54, 525-531 (1987).

A cohesive zone model, taking full account of finite geometry changes, is used to provide a unified framework for describing the process of void nucleation from initial debonding through complete decohesion. A boundary value problem simulating a periodic array of rigid spherical inclusions in an isotropically hardening elastic-viscoplastic matrix is analyzed. Dimensional considerations introduce a characteristic length into the formulation and, depending on the ratio of this characteristic length to the inclusion radius, decohesion occurs either in a “ductile” or “brittle” manner. The effect of the triaxiality of the imposed stress state on nucleation is studied and the numerical results are related to the description of void nucleation within a phenomenological constitutive framework for progressively cavitating solids.

MSC:

74E05	Inhomogeneity in solid mechanics
74C10	Small-strain, rate-dependent theories of plasticity (including theories of viscoplasticity)
74R05	Brittle damage

Keywords:

finite element formulation; cohesive zone model; finite geometry changes; void nucleation; initial debonding; complete decohesion; boundary value problem; periodic array of rigid spherical inclusions; isotropically hardening elastic-viscoplastic matrix