Parametric study and new design recommendations for high-strength stainless steel plate girders under patch loading

High-strength stainless steel (HSSS) is a compelling structural material due to its remarkable strength, costeffectiveness, and excellent resistance to corrosion. Such plate girders are particularly susceptible to patch- loading buckling induced by moving loads. Nonetheless, existing studies have not yet provided specific design recommendations for these HSSS plate girders subjected to patch loading. This study addresses this gap by presenting a comprehensive numerical analysis aimed at developing new design recommendations for evaluating the patch-loading strength of HSSS plate girders made of QN1803 and S32001 materials. A total of 1056 finite element analysis results were reported, investigating the effects of bearing width ratio, web aspect ratio, web slenderness, and initial geometric imperfections. The parametric study results were further used to evaluate the applicability and precision of the current design standards, including the Chinese code (GB 50017) (2017), the European code (EN 1993-1-4) (2006), and the American Specification (ANSI/AISC 360-22) (2022). The comparative analysis revealed that the existing design specifications inadequately predict the patch-loading strength of HSSS plate girders. Consequently, new design recommendations were proposed through the introduction of modified coefficients into the current design rules. Furthermore, a reliability analysis was conducted to evaluate the accuracy of the proposed new equations.