Structural shape optimization of shells and folded plates using two-noded finite strips

Abstract

This paper deals with structural shape optimization of shells and folded plates using two-noded Mindlin-Reissner C(0) finite strips. The whole shape optimization process is carried out by integrating finite strip analysis, cubic spline shape definition, automatic mesh generation, sensitivity analysis and mathematical programming methods in an efficient way. Both thickness and shape variables defining the cross-section of the structure are considered. The objective is to minimize the strain energy with a constraint that the total material volume of the structure remains constant. It is observed that minimization of strain energy leads to optimum structures in which the deflections and stress resultants in the members are considerably reduced. This is illustrated using several examples. The relative contributions of the bending, membrane and shear strain energies are also monitored during the whole optimization process. It is found that most optimal shell and folded plate structures are membrane dominant.