Cross-aisle stiffness analysis of industrial welded cold-formed steel rack upright frames

Abstract In general, industrial cold-formed steel pallet racks consist of upright frames and pallet beams. In the United States, typically, the upright frames are made welding the braces to the uprights. If the brace to upright joints are considered as rigid joints, the stiffness of welded upright frames in the cross-aisle direction obtained numerically is very different from the stiffness obtained experimentally (up to 300% higher). A method is proposed to improve the accuracy of the numerical determination of the stiffness of the frames, by taking into account the semi-rigid behaviour of the brace to upright joints. The semi-rigid behaviour of the joints is analysed experimentally and by simulation with finite elements. The method proposed uses linear behaviour approximation of the frame, and obtains a numerical stiffness that differs only by 10% of the experimental stiffness.