Steel storage racks with locally unstable members

Abstract

This thesis presents comprehensive studies into locally unstable light-gauge steel structures. The aim of this project was to create guidelines for the design of thin-walled steel structures by analyses which consider the effect of cross-sectional instability. Research was conducted to address the knowledge gap associated with the amplification of second-order effects due to local instabilities, the treatment of imperfections in advanced analysis and the effect of interactive buckling on light gauge steel members. The objectives of this research were achieved through a combination of numerical and experimental investigations using two different types of ultra-light gauge steel storage rack uprights. The first series of experiments investigated the effects of interactive buckling through a number of compression tests on varying lengths of ultra-light gauge steel storage rack uprights. The second experimental investigation was used to study the effects of local instabilities on the second-order effects and behaviour of light gauge steel frames. Fourteen full scale storage rack tests were completed using different combinations of beam depths and nominal horizontal loads. Measured imperfection data and calibrated FE models were then used to determine a rational procedure for implementing geometric imperfections into advanced analysis. Special attention was given to the effect that local instabilities had on the second-order displacements of the frame. Based on both the experimental and numerical studies, recommendations were then provided regarding the effect of interactive buckling, inclusion of imperfections in advanced analysis and the effect that local instabilities have on the second-order displacements and ultimate loads of steel storage rack frames.