Decomposition and Two-level Optimization of Structures with Discrete Sizing Variables

Abstract

A generalized decomposition approach is demonstrated for quasiseparable design problems containing discrete variables. Quasiseperable problems involve local design variables and global design variables, shared between subsystems. The primary idea is to assign each subsystem a budget and global system variable values, and require the subsystems to individually maximize their constraint margins. The subsystem constraint margin optimization problems are independent, always feasible, and can be executed concurrently on a parallel machine. An illustrative structural design problem consisting of three beams with discrete cross section selection, reflecting commercially available sections, is presented.