Optimum location of a single longitudinal stiffener with various cross-section shapes of steel plate girders under bending loading

This paper aims at investigating the optimum location of a single longitudinal stiffener having various cross-section types of steel plate girders subjected to bending loading. The optimum location is found using a gradient-based Interior-Point (IP) optimization algorithm. The optimization procedure involves a linear elastic buckling analysis with the finite element method, which is coupled with the aforementioned IP algorithm and used to calculate the buckling coefficient, which is maximized. Based on the optimization results, the effect of the various cross-section types of the stiffener and the web slenderness ratio on the optimum stiffener position is investigated. It is found that closed cross-sections of the stiffener and larger web slenderness ratios lead to higher critical buckling coefficients.