Influence of design parameters on beam-to-column connections of steel storage rack systems

Storage rack systems are the products of cold-formed steel material. Increase in the volume of distant sale in recent years has also increased the importance of logistics and storage industry. In steel storage racks, plug-in beam-end connectors are used to produce boltless and semi-rigid beam-to-column connections. Variability of tab designs for beam-end connector makes it heavily difficult to develop a generalized analytical model. For some typical connectors, several analytical models are available to evaluate the performance of connections. In this study, sixteen beam-to-column connection tests were conducted on a commercially available pallet rack assembly by varying the most effective parameters such as the wall-thickness of the column section, height of the beam, vertical beam position on the connector, and installation of the bolts at connector level among the opening of the column. Being the main goals of this study, failure mechanisms and moment-rotation effects of changing vertical position of the beam on the connector and placing bolts among the opening of the column at the horizontal alignments of the connector, were investigated. These experimental results have shed light on how the ultimate moment capacity, rotational stiffness and rotational ductility values ​​vary by changing these design parameters. In the light of these results, an analytical model has been proposed in order to predict the structural behavior of beam-to-column connections with an acceptable accuracy.