Constrained optimization of anti-symmetric cold-formed steel beam-column sections

Flexibility in the manufacturing of cold-formed steel (CFS) cross-sectional shapes provides a unique opportunity to improve load-carrying capacity these elements, leading more efficient and economic structural systems. This paper presents practical constrained optimization methodology for pin-ended anti-symmetric CFS beam-columns members with different lengths subjected various combinations axial compression bending moment. The process is carried out using Genetic Algorithm (GA) respect buckling resistance elements determined according Direct Strength Method (DSM). In total, 132 three (1000, 2000 3000 mm) eleven cross-sections are optimized under concentrically compressive loads levels eccentricities varying from 0 30 mm. Each cross-section formed certain number fold-lines plate, while length angle constituent considered as main design variables. To provide beam-column end-use constraints well range construction limitations imposed on selected during process. A standard commercially available Z section taken starting point used assess efficiency sections. results show that, given plate width thickness, adopted can significantly increase strength average 62%, 92%, 188% short, medium long respectively, compared those section. It also demonstrated that complex does not necessarily higher members. Finally, verify sections, detailed nonlinear finite element models developed ABAQUS software. should prove useful practice.