Influence of cross-sectional deformation modes on time history analysis of pallet rack structures by means of the Generalized Beam Theory

The influence of cross-sectional deformation modes, such as distortional or local buckling, and the characteristics of member connections are two key factors to determine the structural behaviour of a pallet rack structure. This article therefore aims to analyse the influence of both effects on a pallet rack structure using dynamic (modal and time history) Generalized Beam Theory (GBT) analyses. First of all, the influence of the deformation modes involved in a single cantilever member is assessed by means of a GBT and a Shell transient finite element analysis. The results show good agreement between both models when several cross-sectional deformation modes are involved in the GBT calculation. Next, modal and time history analyses of complete pallet rack structures are carried out using several GBT models. The results indicate that the use of bracings in the down-aisle direction as well as the connection modelling (beam-to-upright and upright-to-brace connections) has a relevant influence on the modal participation of distortional deformation modes, the displacement field, and the longitudinal membrane stress distribution in the columns of the pallet rack structure. Consequently, the paper provides an overview of scenarios in which GBT analysis, which takes cross-sectional deformation into account at low computational cost, is useful for dynamic analysis of pallet rack structures.