Multi-Region Boundary Element Method Implementation for Viscoplastic Analysis

Abstract

This work deals with the implementation of the boundary element method (BEM) for multiregion domain problems, under the hypothesis that the domain is composed of elasto/viscoplastic materials. The Perzyna’s flow rule is adopted in order to achieve viscoplastic responses. The technique adopted to solve the multi-region problem consists of applying the classical BEM to solve separately each region with interfacial nodes restrained against displacements and the other nodes with the specified boundary conditions. Following this, a stiffness matrix is evaluated for each subregion by successively applying the BEM with a unit displacement value prescribed to each degree of freedom correspondent to each interfacial node and direction. By enforcing the compatibility and equilibrium conditions at the interfacial nodes and assembling a global stiffness matrix one can evaluate the displacements at the interfaces, and after this, the remaining unknowns can be obtained. This technique can also be used for coupling BEM and finite element method. The efficiency and accuracy of the BEM implementation are analyzed by means of numerical examples.