Static and seismic analysis of rack structures need to consider several peculiar mechanical features. Uprights are built using cold-formed steel. Cross sections are thin-walled (prone to local and distortional buckling), mono-symmetric (featuring flexural-torsional coupling) and perforated along the whole length; therefore, they require specific treatment. Moreover, joints are based on contact, and they exhibit peculiar nonlinear moment-rotation response already for serviceability loads; while their cyclic seismic response is characterized by pinching with low energy dissipation. Finally, the P-delta effect is critical due to the severe deformability for horizontal loadings and high level of compression of the uprights. All these features induced us to develop a specific solver featuring co-rotational geometric nonlinearities, specific joints, self-evaluation of the upright interaction domain including local and distortional buckling as well as plasticity effects and 7-DoF-per-node beam elements for modelling warping.