Cohesive Discontinuities Growth Analysis using a Nonlinear Boundary Element Formulation

Abstract

The present work deals the development of a nonlinear numerical model for structural analysis of solids composed by multi-domains considering cohesive discontinuities along its interfaces. The numerical method adopted is the boundary element method (BEM), through its singular and hyper–singular integral equations. Due to the mesh dimensionality reduction provided by BEM, this numerical method is robust and accurate for analyzing the fracture process in solids, as well as physical nonlinearities that occurs along the body’s boundaries. Multi-domain structures are modelled considering the sub-region technique, in which both equilibrium of forces and compatibility of displacements are enforced along all interfaces. The crack propagation process is simulated by the fictitious crack model, in which the residual resistance of the region ahead the crack tip is represented by cohesive tractions. It leads to a nonlinear problem relating the tractions at cohesive interface cracks to its crack opening displacements. The implemented formulation is applied to analysis of three examples. The numerical responses achieved are compared to numerical and experimental solutions available in literature in order to show the robustness and accuracy of the formulation.