Ad-hoc cluster and workflow for parallel implementation of initial-stage evolutionary optimum design

Abstract

Numerical optimization and especially topology and shape optimization are typically numerically very comprehensive due to implicit models, large number of variables, high non-linearity, possible infeasibility of candidate designs and related causes. It usually has to be implemented by coupling heterogeneous program environments such as evolutionary optimizers, computer-aided geometric modeling programs and simulators such as finite-element based analysis packages. This paper develops a workflow-based numerical system that serves the purpose of integrating, harmonizing and managing these distinct components in such a way that it provides the functionality needed for the inverse problem of evolutionary initial-stage topology- and shape synthesis. The approach based on inserting and optimizing holes is developed using chained piecewise Bezier curves and/or surfaces for shape parameterization. The procedure developed here employs existing off-the-shelf software packages for computer-aided design, finite element analysis and numerical optimization while building custom middle-ware programs and scripts. It also provides for parallel invoking of different and/or multiple simulators which reduces the optimization run-time by widening the critical bottle-necks in the overall process. The system is implemented inexpensively as an ad-hoc PC-based cluster where individual computers expose server programs and respective services which control locally installed simulators.