A HYBRID BEM FORMULATION FOR MULTIPLE CRACKS IN ORTHOTROPIC ELASTIC COMPONENTS

Local analysis schemes capable of detailed representations of micro-fe atures (e.g, micro-crack interactions) of a problem are integrated wit h a macro-scale BEM technique capable of handling orthotropic elastic components with complex finite geometries and realistic boundary condi tions. The micro-scale effects are introduced into the macro-scale BEM analysis through an augmented fundamental solution obtained from an i ntegral equation representation of the micro-scale features. The propo sed hybrid micro-macro BEM formulation allows decomposition of the com plete problem into two sub-problems, one residing entirely at the micr o-level and the other at the macro-level. This allows for investigatio ns of the effects of the micro-structural attributes while retaining t he macro-scale geometric features and actual boundary conditions for t he component or structure under consideration. As a first attempt, ela stic fracture mechanics problems with interacting cracks at close spac ings are considered. The proposed micro-macro BEM formulation can easi ly be extended to investigate the effects of other micro-features (e.g . interfaces, short or continuous fiber reinforcements, voids, and inc lusions, in the context of linear elasticity) on macroscopic failure m odes observed in structural components.