EVALUATION OF A HOMOGENIZATION-BASED APPROACH FOR ANALYSIS OF METAL MATRIX COMPOSITES BY THE BOUNDARY ELEMENT METHOD CONSIDERING PHASE DEBONDING

Resumo

A formulation of the Boundary Element Method (BEM) to perform analysis of ductile
heterogeneous microstructures considering phase debonding is presented in the context of multi-scale
analysis. The microstructure is modelled by a zoned plate, where different mechanical behaviour can
be adopted for each sub-region. To solve the domain integrals written in terms of in-plane
displacements or plastic forces, the matrix and inclusions domains have to be discretized into cells
where the displacements and forces are approximated. In multi-scale analysis, a point of the
macrocontinuum is represented by a Representative Volume Element (RVE) which in this work, to
model metal matrix composites, is assumed to contain a ductile matrix, rigid inclusions and interface
zone. The rigid inclusions are considered as elastic medium whereas the matrix behaviour is governed
by the Von Mises elastoplastic model with linear strain hardening. The phase debonding is modelled
by a cohesive fracture model using embedded cohesive contact finite elements in the boundary
element mesh. The homogenized results are compared with the ones obtained from a model based on
Finite Element Method (FEM). The accuracy of the results show the capability of the new formulation
based on BEM to deal with complex microstructures.