Stability analysis of cold-formed thin-walled steel members under compression according to AISI S100 standard

Abstract

Cold-formed thin-walled steel members consist of elements that are thin plates, which, when compressed, often experience buckling out of the bending plane, known as the phenomenon of local instability. The AISI S100 Standard provides an effective width method to predict the load-bearing capacity of cold-formed steel members based on the linear instability analysis of the cross-section. This method defines the effective width as the actual width of the cross-section that is considered to remain stable under compression stress up to the yield limit. The calculation instructions of this method are based on the distribution of compressive stresses on the cross-section to assess the ratio of the flat width to the thickness of the compressed element in cases where the cross-section reaches a limit state of stability. This paper analyzes and clarifies the steps for assessing the stability of cold-formed thin-walled steel members under compression according to AISI S100.