Cold-Formed Steel Equal Angles with Complex Edge Stiffeners under Axial-Compression Laboratory Testing, Numerical Simulation, and Design

Abstract

This paper investigates the axial-compression capacity of cold-formed steel (CFS) equal angle sections with complex edge stiffeners. Both experimental and numerical analyses were carried out. In total, 10 tests were carried out and the results are presented in this paper. Preceding to compression tests, the material properties were determined and initial geometric imperfections of all the test specimens were measured. From the results of compression tests, the specimens were all susceptible to flexural buckling. A numerical model was created using the finite-element (FE) software ABAQUS version 6.11. The results of finite-element analysis (FEA) substantiated with the experimental results. The FE models were found to accurately predict the experimental behavior. Thus, the validated FE models were used for a parametric study to analyze the effect of slenderness ratio and the orientation of edge stiffeners on the axial capacity. The axial strengths obtained from parametric study were compared with the design strengths calculated by the direct strength method (DSM) from the American Iron and Steel Institute (AISI) specification. Upon comparison, it was found that the axial strengths calculated based on the current DSM are overconservative by 58% on an average.