Title

A full-space barrier method for stress-constrained discrete material design optimization

Authors

Graeme J. Kennedy

Journal

Structural and Multidisciplinary Optimization

Keywords

Stress constraints, Discrete material optimization, Full-space method, Topology optimization

Abstract
In this paper, we present a full-space barrier method designed for stress-constrained mass minimization problems with discrete material options. The advantages of the full-space barrier method are twofold. First, in the full-space the stress constraints are provably concave, which facilitates the construction of convex subproblems within the optimization algorithm. Second, by using the full-space, it is no longer necessary to employ stress constraint aggregation techniques to reduce adjoint-gradient evaluation costs. The proposed optimization algorithm uses a Newton method where an approximate linearization of the KKT conditions is solved inexactly at each iteration using a preconditioned Krylov subspace method. Sparse constraints that arise in the discrete material parametrization are treated using a null-space method. Results of the proposed algorithm are demonstrated on a series of three topology and multimaterial optimization problems with selection between isotropic and orthotropic materials, as well as discrete ply-angle selection.

Link
http://link.springer.com/article/10.1007/s00158-016-1428-z