Comparative experimental studies on the web cleat bolted CFS beam-to-column connection

Abstract

Cold-formed steel (CFS) clip angles/web cleats are widely used as connectors between two CFS members. This study aims to determine the efficiency of a three bolted web cleat over a two-bolted web cleat joint between the beam-column predominantly subjected to a shear load. A total of 26 specimens were studied to investigate the three bolted web cleat configuration by considering two different parameters: (i) thickness of the web cleat (TC) and (ii) the aspect ratio (L/B) of the web cleat leg attached to the column. The experimental results show that the ultimate load increases with a decrease in the aspect ratio of the web cleat leg attached to the column. In addition, the experimental loads of three-bolted configuration were 13 to 95% higher than the corresponding two-bolted configuration. Two types of failure modes were observed: (i) local buckling and (ii) bearing failure of CFS beam under the loading points. The lateral deflection of the column, relative rotation of the connections, and vertical deflection under the loading points were measured and analysed. The nominal shear values calculated from available equations in the past studies are over-conservative when compared to the observed experimental shear values. Hence, a new design equation is suggested for the design of three-bolted web cleat configuration with some specified limits. Besides, reliability studies were performed for the existing and proposed equations for the design of web cleat with three-bolt configuration.