Web crippling behaviour of cold‐formed high‐strength steel unlipped channel beams

AbstractConstruction industries have increasingly sought to adopt Cold‐Formed Steel (CFS) sections as primary and secondary load‐carrying members. Also, the evolution of the CFS industry leads to fabrication of high strength CFS sections due to their added benefits such as higher strength‐weight ratio, most appropriate to employ in high‐rise and long‐span applications, and lesser carbon footprint. However, large width‐to‐thickness ratios of these thin‐walled beams make them vulnerable to local buckling failure, a major failure mode being web crippling when subjected to concentrated loads. The design standards predict the web crippling capacity of CFS sections according to the experimental studies conducted in previous years. Innovative concepts like the production of CFS using high‐strength materials should be examined undergoing web crippling. Therefore, the web crippling behaviour of the unlipped channel sections with material strength up to 1000 MPa under all four loading conditions: End‐Two‐Flange (ETF), Interior‐Two‐Flange (ITF), Interior‐One‐Flange (IOF) and End‐One‐Flange (EOF) was investigated in this study. Numerical simulations using Finite Element Analysis (FEA) software (ABAQUS) were conducted on 972 parametric studies following proper validation. New modified equations were proposed to predict the ultimate web crippling capacity of high strength unlipped channel sections and parametric analyses were carried out among various loading conditions.