Experimental Study of Cold‐formed Steel Frames with Semi‐rigid Floor‐to‐wall Joints

Abstract In conventional cold‐formed steel (CFS) structural design, floor‐to‐wall joints are generally considered pinned and, thus, incapable of transferring moments. However, recent studies have shown that the use of semi‐rigid connections can lead to more efficient and economical frame designs. This paper presents an experimental investigation into CFS frames with semi‐rigid joints, comprising a series of full‐scale tests on CFS frames with varying joint stiffnesses, varying joist and stud dimensions and different screw arrangements between the steel joists and timber boarding. Digital image correlation (DIC) was employed to monitor rotations and the buckling behaviour of the joists in detail. The joint rotational stiffness was found to have a significant influence on the limit states of the CFS frames, while it was shown that optimised combinations of joist and stud dimensions, along with appropriate screw arrangements, can further enhance structural efficiency.