Topological derivative-based topology optimization of structures subject to Drucker-Prager stress constraints

An algorithm for topology optimization of elastic structures under plane stress subject to the Drucker-Prager stress constraint is presented. The algorithm is based on the use of the topological derivative of the associated objective functional in conjunction with a level-set representation of the structure domain. In this context, a penalty functional is proposed to enforce the point-wise stress constraint and a closed formula for its topological derivative is derived. The resulting algorithm is of remarkably simple computational implementation. It does not require post-processing procedures of any kind and features only a minimal number of user-defined algorithmic parameters. This is in sharp contrast with current procedures for topological structural optimization with local stress constraints. The effectiveness and efficiency of the algorithm presented here are demonstrated by means of numerical examples. The examples show, in particular, that it can easily handle structural optimization problems with underlying materials featuring strong asymmetry in their tensile and compressive yield strengths. (C) 2012 Elsevier B.V. All rights reserved.