Design reliability analysis of cold-formed thin-walled steel members with S280 hard-rolled steel sheets

Abstract:

Based on the data including the yield strength, the dimensions of sections and the load-carrying capacity of existing experiments on axially-compressed members, eccentrically-compressed members and bending members，the uncertainty of material strength, geometric characteristics and calculation mode of S280 cold-formed thin-walled steel with thickness no more than 2mm was analyzed. Then, the improved second-order moment probability method was used to check the required reliability index of S280 cold-formed thin-walled steel sections with thickness no more than 2mm using the resistance partial factor in current codes under deferent load combinations. The results show that, using the recommended resistance partial factor in current codes, the reliability indexes of the axially-compressed members, the eccentrically-compressed members and the bending members with width-thickness ratio within the limitation of current codes can well meet the target reliability index. Finally, the recommended design strength value of S280 cold-formed thin-walled steel sheets with thickness no more than 2mm was proposed for structural design.