Stiffened steel plates under combined compression and bending

Abstract

This paper presents part of a series of investigations of the behaviour of steel plates stiffened with tee-shape stiffeners and loaded with axial compressive forces with or without bending moments. These elements typically form bridge decks, ship hulls, ship decks and heavy haul equipment walls. Earlier work by the authors validated a non-linear large deformation-finite strain elasto-plastic finite element model by comparison of the model with the results of sophisticated full-scale physical experimental trials under different load combinations. A parametric study carried out using the finite element model is presented in the following. The study deals with the response of stiffened plate elements under combined uniaxial compression and bending moment. The parameters investigated were the transverse slenderness of the plate, the slenderness of the web and flange of the stiffener, the ratio of torsional slenderness of the stiffener to the transverse slenderness of the plate, and the stiffener to plate area ratio. Average magnitude residual stresses and initial imperfections were assumed. The parametric study indicated that the plate transverse flexural slenderness is the most influential parameter affecting both the strength and behaviour of stiffened steel plates for all the failure modes observed under combined compression and bending. The ratio of stiffener torsional slenderness to plate transverse flexural slenderness, β4, affected both the strength and behaviour of only the stiffened plates failing by stiffener tripping. A comparison of the numerical analysis results with American Petroleum Institute and Det Norske Veritas design guidelines indicates that the guidelines predict stiffened steel plate capacity with various degrees of success, depending on the governing mode of failure.