Ultimate longitudinal compressive strength of steel plates with lateral patch load induced plastic deformation

The aim of the present study is to investigate the influence of large plastic deformation caused by lateral patch load on longitudinal compression behaviour of steel plates. A series of nonlinear finite element analyses are undertaken with a two-step procedure. Plastic deformation is induced in the first step by applying lateral pressure as a patch on the plate and the plate is subjected to monotonically increasing unixial compression load in the second step up to and beyond collapse. The residual stresses resulting from plastic deformations are retained in the collapse analysis. The plates are also analysed in intact condition. The effects of lateral patch load width and permanent set amplitude, as well as plate slenderness ratio are examined. The results reveal that the damage reduces the pre-collapse stiffness of the plates significantly. In addition, as plastic deformation is more localised, its detrimental effect on plate ultimate strength is more severe.