Optimization of cold-formed steel pallet racking cross-sections for flexural–torsional buckling with constraints on the geometry

Starting from a comprehensive set of experimental test results of upright cross-sections in compression, this paper is focussed on how the section can be optimally designed to achieve the highest possible failure load in global buckling. The aim is to optimize a cross-section prototype shape with restrictions on its geometry attending to manufacturing feasibility and assembly constraints. The proposed scheme consists of maximizing the design strength with respect to flexural–torsional buckling, according to European Standard prEN 15512:2008 [European Standard prEN 15512:2008. Steel static storage systems - Adjustable pallet racking systems - Principles for structural design] / Fédération Européenne de la Manutention [Fédération Européenne de la Manutention (Section X): The design of static steel pallet racking. FEM 10.2.02; August 2000] design recommendations. This is a bicriteria optimization problem which is solved by formulating a nonlinear mathematical program. Optimization is performed prior to the finite element method (FEM) nonlinear analysis of the solution design. The procedure herein presented has two advantages: on the one hand it considerably reduces the number of nonlinear analyses, and on the other it ensures that the best design is achieved.