Global-local structural optimization using response surfaces of local optimization margins

A general decomposition method developed by Haftka and Watson is applied to global-local structural optimization problems. First, a large number of component optimizations for maximization of margins are performed. Response surface approximations (RSAs) for maximum margins of component optimization are constructed. At the system-level optimization, the RSAs of maximum margins are used as surrogates for the components. One advantage of the decomposition approach is that it allows much of the search for a global optimum to be conducted in low dimensions for each component separately. Minimization of a portal frame weight with eight local optima is used to demonstrate the approach.