Thin-walled open cross-section members, such as those used in rack structures, suffer section deformations, which significantly affect their stiffness and, consequently, their dynamic behaviour. Three different numerical models of such a member are presented in the paper: one using beam finite elements, another using shell finite elements, and the third one using Generalized Beam Theory (GBT) based finite elements. The models include point masses in order to simulate the weight of pallets stored on the structure. The viability and accuracy of the GBT model are investigated by carrying out modal, harmonic or transient analyses. The natural frequency and the displacement field of several modes obtained through the three modal analyses (the three models) are compared, as well as the displacement fields in harmonic and transient analyses. The main objective of this paper is to describe how accurate the GBT can be in analysing the dynamic behaviour of pallet rack members by comparing the results obtained through the GBT and the shell models. It also describes its limitations and the influence of perforations on the results. With regard to the beam models, this paper points out how the inability of the beam models to represent in-plane section deformations affects the results. Consequently, this paper also points out the improvement that the GBT brings to this type of analysis.