Fracture Model of Bimaterial under Delamination of Elasto-Plastic Structured Media

Abstract

Delamination of bimaterial composed of two structured materials is considered. A crack is located at the interface between two media. Under tension applied at infinity, I mode fracture is implemented. The improved Leonov-Panasyuk-Dugdale model (LPD model) is proposed to be applied in combination with the Neuber-Novozhilov approach. The case when elastic material characteristics are identical and strength ones essentially differ is analyzed in detail. Analytical description of plotting the fracture diagram of quasi-brittle bimaterial for the plane stress state is given. Numerical modeling of the plasticity zone in bimaterial under quasi-static loading has been performed. The updated Lagrange formulation of solid-state mechanics equations is used in a numerical model. This formulation is most preferable for modeling of bodies made from elasto-plastic material subjected to large strain. Using the finite element method, a plastic zone in the vicinity of a crack tip has been described. It is shown that the shape of the plastic zone in bimetal essentially differs from that in a homogenous medium. Numerical experiments are in good agreement with the proposed analytical model of the pre-fracture zone in the weakest material.

Damage Accumulation and Fracture of Weld Joints under Low-Cyclic Loading Conditions

“…Here w < ∞ is the plane specimen width, ( ) for bimaterial [14,15]. The Young's modulus of the bimatrial components are considered to be coincident, the yield strengths of the materials differ ( Y σ is the least yield strength), Damage Mechanics: Theory, Computation and Practice delamination occurs along a plane interface between materials.…”

“…. Embrittlement of the bimaterial takes place as compared to the homogenous material since the pre-fracture zone of the bimaterial is two times narrower than that of the homogenous material [14,15].…”

“…Recent results [23] concerning weld seams when these are delaminated indicate that there exist various schemes of fracture, but the scheme of delamination of bimaterial can be considered as principal [14,15]. Study the process of bimaterial delamination under conditions of fatigue loading.…”

Delamination of Bimaterial and Critical Curves of Quasi-Brittle Fracture in the Presence of Edge Cracks

“…results in profound rearrangement of plasticity zones (pre-fracture zones) in the vicinity of a crack tip [11] located along the interface. The excellent illustration of plasticity zones and possible mechanisms affecting energy dissipating in homogeneous materials under repeated loadings are given in Figs.…”

“…Thus, the proposed fracture criteria [2][3][4] are two-parameter. The employed crack tip opening displacement (CTOD) is directly related to the pre-fracture zone width that allows arrangement of plasticity zones in bimaterial and their effect on fracture process to be taken into account [11] (bimaterial is a composite material with the plane interface).…”