On the Effectiveness of the Iterative Coupling FEM–BEM for the Analysis of the Problems with Elastoplastic Failure Behavior

The main purpose of this paper is to investigate the interface relaxation FEM–BEM coupling method to resolve problems involving nonlinear fracture mechanics. In this coupling technique, the nonlinear portion near the crack tip is modeled by the finite element method (FEM) and the remainder of the domain which is linear elastic is discretized using the boundary element method (BEM). In the coupling procedure adopted here, there is no need to combine the coefficients matrices of FEM and BEM subdomains and separate computing for each subdomain with successive renewal of the variables on the interface are performed to reach the final convergence. To demonstrate the effectiveness of the developed approach, several practical problems of nonlinear fracture mechanics are analyzed. The conventional FEM computations are also performed, and a critical comparison of the results is made.