Strength behaviour of column studs in prefabricated wall panels using cold-formed steel

Abstract

A full-scale experimental study on the strength behaviour of individual studs and column studs in a prefabricated wall panel is presented in this report. The individual stud and the panel are made of cold-formed steel sections with a dimension of 3 m height, and 3.15 m height and 1.5 m width respectively. At the moment, the British Code has not provided adequate detail design to account the load capacity of a cold-formed steel column stud in a prefabricated wall panel. The structural performances of column stud therefore need to be obtained through the experimental investigation. A total of five specimens were tested in pure axial compression until failure. The specimens consist of three specimens with one type of lipped C-channel designated here as S350CT1, S350CT2 and S350CT3, one specimen of I-section, D350CT1 and one specimen of wall panel, W350CT1. Comparison between experimental values for column stud in the wall panel and experimental values for the individual studs were made. Experimental values for the individual studs were also compared with the theoretical values computed based on BS 5950-Part 5:1998 Code of practice. All individual studs which were subjected to pure axial compression, except the S350CT1, failed due to flexural buckling (FB) mode, with a substantial visible permanent deformation and without significant torsional buckling. S350CT1 failed due to shearing of the bolts in the bolted connection. From the investigation, it can be concluded that the selection of section geometries affect the failure stress capacity of individual studs dramatically. All individual stud failure loads obtained experimentally are in good agreement with the predicted values. As for the prefabricated wall panel, it was found that a flexural buckling and local buckling had occurred in the wall panel as the wall panel reaching the failure, and subsequently the ultimate load.