FREQUENCY AND VEHICLE-BRIDGE VIBRATING ANALYSIS OF SKEWED BRIDGES CONSIDERING SHEAR DEFORMATION EFFECT

Modified Timoshenko beam theory was used to establish the transcendent equation of vibrating frequency and finite element formulations for static and dynamic analysis. The first five order frequencies were obtained by analytic method and finite element method, which depend on obliquity and supporting manners. The interaction of vehicle-bridge system for single span skewed bridge was studied, and the vehicle velocity was found to affect the dynamic deflection and dynamic moment, synchronization of different cross-section, and the positions of maximum dynamic deflection and dynamic moment. Impact factors of deflection and moment calculated by bridge specification method and vehicle-bridge system method for different vehicle velocities were compared, indicating that (1) theoretic vibrating frequencies are consistent with finite element results for skewed bridge, (2) obliquity and supporting manner have significant influences on dynamic characteristics, (3) the impact effect and velocity of vehicles do not change monotonously, and (4) the impact factors of deflection and moment are different for skewed bridge.