Review on Impacts of Geometric Imperfections on Behavior of Cold-Formed Structural Members

Cold-formed structural members have been demonstrated to be highly sensitive to buckling modes due to their small thickness. Cold-formed sections have been identified to exhibit significant geometric imperfections which have been illustrated to significantly affect the stability and should be considered in structural analyses of such cold-formed structural members. Their effects were presented in a variety of previous investigations, but these obtained results were still discrete without general evaluations. Therefore, this paper will provide an overview on the impacts of various imperfection components on the behavior of cold-formed structural members. Subsequently, several previous investigations on structural behaviors of cold-rolled structural members were summarized and thoroughly analyzed to enhance understanding of the influence of each geometric imperfection component. It was found that sectional imperfection components should be considered in the analyses for short and intermediate structural members whereas global imperfection components should be included in the analysis of long structural members. Also, bucking behaviors of a structural member were governed by combinations of various imperfection components instead of any single component. These findings will be the base for future investigations of such members under the effects of geometric imperfections.