Optimal Elastoplastic Structural Design Using Sensitivities by Incremental Procedure

Abstract

This paper describes a method for structural optimization considering the elastoplastic structural behaviour. The proposed method consists of three parts : elastoplastic incremental structural analysis, elastoplastic sensitivity analysis, and optimization. The structural analysis and sensitivity analysis are performed using the incremental finite element method. For structural optimization, the Sequential Unconstrained Minimization Technique (SUMT) is used.In the optimization process, reanalysis is performed using the elastoplastic sensitivities. To get rational reanalysis solutions, some limitations should be imposed on the magnitude of changes in design variables. The maximum allowable changes in design variables are automatically evaluated by applying repeated sensitivity analysis during the optimization process.After verifying the accuracy of the reanalysis solution based on repeated sensitivity analysis, a three-bar and a ten-bar plane trusses are analyzed taking the cross-sectional areas as design variables. Comparison of the results shows that the proposed method gives very good results.