Improved Shear Buckling Resistance Model for High Strength Steel Plate Girders

Abstract

This paper presents an improved shear buckling resistance model for high‐strength steel (HSS) plate girders. The EN 1993‐1‐5 formulation is enhanced by revising the plastic hinge location in the flanges and consistently accounting for the relative contributions of web, flanges, and stiffeners, resulting in a more accurate representation of post‐buckling behaviour. A validated finite element model is used to perform a parametric study on welded I‐girders in S355 and S690, covering web slenderness, panel aspect ratio, flange‐to‐web section modulus ratio and stiffening configurations. The proposed model improves agreement with numerical results, increasing the mean VFEM/Vmodel from 1.09 to 1.12 and reducing the CoV to 10.6%, while markedly reducing unsafe predictions. The model delivers consistent accuracy across unstiffened, transversely stiffened, and longitudinally stiffened girders, eliminating unconservative predictions in EN 1993‐1‐5 at high flange‐to‐web ratios. Reliability analysis confirms reduced scatter and lower partial resistance factors, with γ*M1 decreasing from 1.05–1.08 to 1.01–1.02 for both S355 and S690.