Shear strength of horizontally curved steel I-girders — finite element analysis studies

Abstract

This paper presents the results of finite element analysis (FEA) studies of four curved steel I-girder shear components tested experimentally in previous research, as well as parametric extensions of these tests. These studies focus on the influence of horizontal curvature on the maximum strength of transversely stiffened members with web slenderness D / t w approximately equal to the largest value permitted in AASHTO [AASHTO LRFD bridge design specifications. 3rd ed. In: 2005 Interim Provisions, Washington (DC): American Association of State and Highway Transportation Officials; 2004], and with panel aspect ratios of d o / D = 1.5 and 3.0. These ratios are larger than previously considered in experimental tests of curved I-girders with similar or larger slenderness. The girders studied have subtended angles between their bracing locations of L b / R = 0.05 and 0.10, and web panel d o / R values ranging from 0.03 to 0.10. The FEA models incorporate the measured material stress–strain relationships and section dimensions from the physical tests, detailed modeling of the test boundary conditions, residual stresses due to flame cutting and welding, and initial geometric imperfections in the form of buckling mode shapes. The load transfer mechanisms of the test girders are investigated via elastic buckling and full nonlinear analyses. The parametric studies are performed to investigate the effects of residual stresses and geometric imperfections, the behavior of equivalent straight girders, and the influence of reduced flange size on the peak shear capacity and moment–shear interaction.