Stiffener tripping in stiffened steel plates

The stability of stiffened steel plates with tee-shaped stiffeners under uniaxial compression and combined compression and bending was investigated using a finite element model. The emphasis of work presented in this study is to first identify the parameters that uniquely characterise the behaviour and strength of stiffened steel plates and then to conduct a parametric study aimed at identifying the conditions that may lead to failure by tripping of stiffeners.;The study was conducted using a finite element model that was validated from a comparison of predicted behaviour and strength from a series of tests on full-scale test specimens. The numerical study indicated that the behaviour of stiffened steel plates could be characterised by non-dimensional geometric, initial conditions and loading parameters.;A numerical parametric study was conducted on the geometric part of the proposed parameters set with the parameters controlling initial conditions set to the most probable values. Only two types of loading conditions were investigated. In the first, uniaxial compression was applied to obtain the failure condition and in the other combined bending and compression were applied.;The study indicated that the stiffener tripping failure of tee-shape stiffeners require the application of a bending moment, causing a compressive stress in the flange of the stiffener.;The numerical analysis results show inconsistent capacity predictions by current API (American Petroleum Institute) and DnV (Det norske Veritas) design guidelines.