Evaluation and modelling of the material properties for analysis of cold-formed steel sections

The results of two series of experimental investigations to evaluate the mechanical properties and the residual stresses of cold-formed steel (CFS) sections are reported in this paper. These investigations were performed on channel-shaped CFS sections manufactured using cold-roll forming technique. Tensile coupon tests were used to evaluate the mechanical properties at different positions of the channel sections. Electrical resistance strain gauges with an "Electrical Discharge Machining" cutting technique were used to establish the magnitudes and the distributions of residual stresses within the channel sections. Based on the experimental results, appropriate analysis models for the stress-strain relationship, the variation of the yield strength, and the residual stresses in CFS channel sections are established. These models are incorporated within a large deformation shell finite element to form a model for cold-formed steel sections. The finite element model is evaluated against experimental results of CFSsections in compression.