Shear behavior of steel plate girders considering variations in geometrical properties

Abstract

This paper presents equations to determine the ultimate shear strength reduction factor of web plate in steel plate girders due to initial imperfection. The proposed equations are based on a parametric study of shear behavior of steel plate girders considering variation in geometrical properties of the section. 112 models with various initial imperfections, flange-to-web stiffness ratios, and web slenderness were analyzed using finite element software ABAQUS. Both geometric and material nonlinearity have been considered. According to the results, the ultimate shear strength proposed by AISC code is conservatively less than the obtained results by FEM, especially for slender plates; the difference between these two values could reach up to 60% in some cases. That is while, for compact and non-compact web plates, maximum difference is about 10%. Furthermore, it is observed that AISC elastic shear buckling strength is conservatively less than the results derived from FEM. This difference in slender and compact web plates reaches to almost 40% and 20%, respectively. This study reveals that the initial geometrical imperfection is an effective parameter on the shear strength of web plates. According to the results, the sensitivity of girders to initial imperfection is greater in non-compact-web girders than the slender or compact ones, and the maximum shear strength reduction is observed about 23% for maximum allowable imperfection as recommended in part1–5 of EC3. Based on the obtained results, a maximum permissible construction tolerance is proposed as well.