Optimal design of thin-walled open cross-section column for maximum buckling load

Abstract

In this work, a finite element based optimization methodology is developed to obtain the optimal designs of thin-walled open cross-section columns for maximum buckling load. As a constraint for the optimization study, the total material volume of the column is kept constant. At first, an analytical formulation based on Bleich's (1952) approach, which considers the combined effect of both torsional and flexural buckling, is used to validate the finite element buckling load computation in ANSYS. Subsequently, these finite element buckling results are coupled with a Genetic Algorithm (GA) based optimization routine in MATLAB to obtain the optimal design of the cross-section of the columns. Optimal results are compared with a base model of the column having a cruciform cross-section. The optimization of the cross-sections results in remarkable enhancement, up to as high as 236%, in the maximum buckling load capacity compared to the base model.