Numerical analysis of cold-formed double angles back-to-back under compression

Abstract Here-in, a numerical analysis based on the Finite Element Method (FEM) is proposed in order to investigate cold-formed steel back-to-back double angle structural behavior under compression. Considering non-linear analysis, an investigation was performed to analyze the influence of some aspects, such as the loading condition (concentric and eccentric axial compression), the boundary conditions, the global slenderness, the global and local geometric imperfections, the angle thickness and the number of packing plates. The numerical results signalize that the compression strength obtained in accordance with the standards ABNT NBR 14762:2010 and ANSI/AISI S100 (2012) may be quite conservative, mainly in the lower global slenderness cases. Additionally, the connection spacing (bolted connection with stitch plates in-between the angles) and the presence of a connection at mid-length change the buckling mode, as well as cause a significantly increase in the axial compression strength of the member. The numerical analysis also indicates that the design proposed by ABNT NBR 8800:2008 for the case involving angles under compression connected by one flap can also be applied to cold formed steel angles