Behavior of steel pallet rack beam-to-column connections at elevated temperatures

Abstract

Beam-to-column connections (BCCs) in steel pallet racks (SPRs) govern the stability of the structure in the down-aisle direction and possess a complex behavior as compared with the customary steel connections used in building structures because of the absence of bolts and welds. This behavior becomes increasingly complicated in case of hazardous conditions, such as fire, and needs careful design considerations. Warehouse fires are associated with higher average property losses per fire than most other occupancies. The existing literature completely lacks the studies focusing on the behavior of SPR BCCs under fire. This paper predicts the experimental and numerical behavior of SPR BCCs subjected to elevated temperatures. Eight sets of connection specimens, with three specimens in each set, were selected based on the variation in column thickness, beam depth, and the number of tabs in the beam end connector. A total of twenty-four tests were performed at three different temperature ranges (450°C, 550°C, and 700°C) using the double cantilever test method. The major failure modes and the moment-rotation (M-θ) behavior of the SPR BCCs at elevated temperatures were evaluated and compared with the results of ambient temperature testing of SPR BCCs available in the literature. The findings indicated a noticeable degradation in the strength and stiffness of the connection due to thermal action. A non-linear three-dimensional (3D) Finite element (FE) model was developed to simulate the experimental investigations. The FE model exhibited a close agreement with the experimental results.