Influence of residual stresses on the behaviour of flat and curved steel plates

In this paper, the weld-induced residual stresses are modelled and their influence on the behaviour of flat and curved panels with stiffeners is analysed. The ultimate strength of shell-like structures, both flat and curved, is governed by the interaction of plate local and global buckling and is therefore highly affected by imperfections, namely geometric imperfections and residual stresses. Their origins are in the production (hot rolling) and treating (cutting, welding) processes of plated structural elements. To investigate more in-depth the effects of residual stresses, a large numerical parametric study is performed. Different amplitudes of residual stresses are taken in account together with other important geometric parameters, such as curvature, aspect ratio and plate slenderness. A linear buckling analysis (LBA) is performed in order to provide initial geometric imperfections for the further conducted nonlinear analysis (GMNIA) with residual stresses. Finally, the effects of residual stresses on the behaviour of stiffened panels and their ultimate strength are investigated.