The Influence of Residual Stress Due to Cold Bending on Thin-Walled Open Sections

Abstract

<p> This thesis deals with the analytical and experimental study of the influence of residual stress due to cold bending on the behaviour of thin-walled open sections. The residual stress distribution caused by cold forming the sections is predicted theoretically. The influence of this residual stress on the load-displacement characteristic, and load carrying capacity of similarly curved tension and compression specimens is then analyzed. A local buckling analysis based on the virtual work and incremental theories is performed to predict the collapse load of compression specimens containing residual stresses.</p> <p> The experimental work consisted of tests to confirm theoretical elastic springback strains due to cold bending of steel sheet to various radii. Tension and compression tests were then performed on various cold formed sections to observe the effects of residual stress and to confirm analytical predictions. </p> <p> Conclusions have been deduced from the theory and from these tests, and suggestions made for further research.</p>