A new approach to finite deformation problems of elastoplasticity—boundary element analysis method

Abstract A formulation and numerical implementation of boundary element methods (BEM) for the finite deformation problems of elastoplasticity is presented in this paper in updated Lagrangian description. This formulation has considered two kinds of traction rates. The velocity-gradient equation of inner point is fully deduced to meet the desire of higher order elements and cells. A scheme of iteration suitable for J 2 -flow theory is developed, too. Moreover an effective indirect quadrature is designed to overcome the diffuculty of evaluating Cauchy principal values of domain integrals; owing to this the quadratic isoparametric elements and cells are successfully introduced in the code BELEPA. Several numerical examples, including the necking of plate specimen, are presented at the end. An interesting phenomenon is observed from the results that the BEM analysis of necking is more sensitive to the initial imperfection of specimen than FEM analysis. Further investigation is needed to confirm this phenomenon.