Influence of the cold work effects in perforated rack columns under pure compression load

• Definition of the residual stress pattern for a perforated rack column.
• Evaluation of strength enhancement in corner areas of a rack section.
• Inclusion of residual stresses and strain hardening in a nonlinear buckling analysis of a perforated rack column.
• Comparison of FEA and experimental results.

This paper analyses the influence of residual stresses and strain hardening due to the cold roll-forming process on the load carrying capacity of perforated rack columns. First of all, a residual strain distribution of the manufacturing process is obtained via a finite element analysis and then it is introduced in the model as initial state to carry out a nonlinear buckling analysis. Two different methodologies to introduce the residual strain pattern are presented in order to reproduce the local stress effects because of perforations. Moreover, the changes of the mechanical properties of the material by strain hardening are evaluated through experimental tests and its influence on the rack column behaviour is investigated. The results obtained agree well with experimental tests and show a method to predict the load carrying capacity of perforated rack column taking into account the effects of the cold roll-forming process.