Effects of cross beams on free vibration of horizontally curved I-girder bridges

Due to the initial curvature of horizontally curved I-girder bridges, their out-of-plane behavior exhibits the flexural and torsional motion simultaneously. Unlike the dynamic and static responses of straight bridges, those of curved bridges are significantly affected by cross beams and the initial curvature of girders. In the present study, the finite element analysis is used to investigate cross beam effects on free vibration of horizontally curved I-girder bridges with varying modeling methods, degrees of freedom, cross sections and numbers. Free vibration analyses of horizontally curved I-girder bridges are performed with the finite element analysis program developed based on the theory of thin-walled curved beams. The bridge is modeled as a 3-dimensional grillage beam system composed of curved beam elements and straight beam elements. Both of those elements have 7 degrees of freedom per node including the warping degree of freedom.