Cross-aisle stiffness analysis of industrial welded cold-formed steel rack upright frames. (August 2019)

• Record Type: Journal Article
• Authors: Roure, Francesc; Peköz, Teoman; Somalo, M. Rosa; Bonada, Jordi; Pastor, M. Magdalena; Segura, Amadeu
• Is Part Of: Thin-walled structures. Volume 141(2019)
• Page Start: 332
• Page End: 344
• Publication Date: 2019-08
• Subjects: Thin-walled structures -- Periodicals; 690.1
• DOI: 10.1016/j.tws.2019.04.041
• Languages: English
• ISSNs: 0263-8231

Abstract

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. Highlights: Shear stiffness of welded frames assuming rigid brace- upright joints over-estimates the actual stiffness of the frames. The reason is that the brace – upright joints are not rigid, and their deformations have to be taken into account. The stiffness of the joints has been obtained by simulation with finite elements and the results verified experimentally. By introducing the stiffness of the joints in the FE model of the frames, a very good agreement is obtained. The influence of the axial load acting on the upright on the behavior of the brace – upright joints has also been analyzed,