Comparison between numerical models for unbraced multiple bay pallet racks

Abstract

Unbraced pallet racks are cold‐formed steel structures intended for the storage of products. They are subjected to severe lateral actions, and are particularly instability prone in the down aisle direction. Therefore, their design is compromised and needs of an accurate modelling. In current design practice, models using simplified beam formulations are regularly considered (such as Euler‐Bernoulli or Timoshenko), being them not able to reproduce torsional warping, or cross‐sectional distortion; these phenomena are accounted for indirectly via reduced sectional properties, and in the post‐process. This paper presents a comparison between three single column models, intended for the modelling of racks with a significant number of bays. Three models are presented: –Two 2D beam models using gross and equivalent section properties –A 3D beam model using equivalent section properties. Additionally, the results of these analyses are compared with those of a 3D model using shells and beams, presented in a previous research paper. Two rack configurations with different level heights are considered. The aim of this study is to capture the influence perforations of the uprights, warping, eccentricities and cross‐sectional distortion in the nonlinear response of racks subject to severe lateral actions.