2018 Volume 2018 Pages 20180009
Recently, primal-dual interior-point method (IPM) are focused as an efficient strategy for large scale contact problems. Contact algorithm based on IPM, however, is difficult to apply finite deformation problems. These problems should be divided into some loading steps and slave nodes approach master surface to very close. Too strong contact reaction force then occurs at the beginning of Newton-Raphson (NR) loop in a loading step. This force causes instability of computation. In this paper, we present contact algorithm based on IPM with warm-start method for solving this problem. Contact constraints are relaxed by additional variables. We solve some problems, including a large deformation problem, and compare the number of NR iteration to investigate convergence of contact analysis. As a result, we find that the proposed method improves convergence of contact analysis from standard IPM and conventional active set method.
