Lateral-torsional buckling of high-strength steel beams under stochastic corrosion-induced mass loss

Most studies on high-strength steel (HSS) structures focus on the design of new components; However, ensuring long-term reliability is crucial under corrosion. This article examines the impact of stochastic pitting corrosion on the lateral-torsional buckling (LTB) resistance of HSS beams. A stochastic finite element analysis framework showed that LTB resistance exponentially degrades with mass loss, reaching up to 39% degradation for severe corrosion. Characteristic bending resistance parameters were established based on 10,170 nonlinear buckling simulations, 6562 elastic eigenvalue evaluations, and 6275 fiber section analyses. A comparison with simplified finite element models shows that while the elastic critical moment can be accurately predicted, cross-sectional moment resistance and buckling capacity tend to be overestimated. Eurocode 3 provides a substantial safety margin when predicting the LTB capacity of corroded HSS beams.