Cold Rolling Effects on Material Properties in Pallet Rack Uprights

Abstract

Pallet rack structures are usually made up of thin walled cold formed steel sections. The cold rolling process changes the material properties, increasing the yield strength and tensile strength across the section. According to EN1993-1-3, an equivalent yielding strength is allowed to be considered in design to account for the changes in material properties. It has to be mentioned that this approach does not take into account the residual stresses that arise following the forming process. The current paper presents the experimental evidence of residual stresses as result cold rolling process for two pallet rack upright sections. Based on experimental findings, a series of numerical models were created in order investigate the influence of residual stresses onto the load bearing capacity of pallet rack uprights. The experimental program was developed within the CEMSIG Research Centre (http://cemsig.ct.upt.ro) of “Politehnica” University of Timisoara. The increase of yield strength and tensile strength across the cross-section was also experimentally determined.