Plate and stiffener buckling in transversely loaded steel panels

Abstract

Stiffened plates may be loaded by axial forces in two directions, i.e., along and transverse to the stiffeners, by in-plane shear force, and by out-of-plane loads as from traffic or water pressure. Special care must be taken for buckling effects caused by the compressive in-plane forces.

The buckling behaviour of plates stiffened with four trapezoidal stiffeners was investigated for the case of compressive axial force directed transverse to the stiffener direction. The width and length of the stiffened plate and the ratio between the plate- and stiffener stiffnesses were varied. The investigation aimed to determine criteria to ensure that the dominating buckling mode was either buckling of the plate between the stiffeners, or a predictable buckling pattern of the stiffeners. For this, two formulas are presented, giving the necessary plate-to-stiffener stiffness ratio or the maximum length of the panel. Furthermore, capacity approaches for the axial resistance for transverse axial loading are studied, applying the Effective Width Method (EWM) and the Reduced Stress Method (RSM). Comparisons with nonlinear FE-simulations show that the predictions range from 45% to 99% of the FE-results.