Vehicle–Bridge Coupling Vibration Analysis of Long-Span Self-Anchored Suspension Bridges Based on Cross-Section Mass–Shear Center Heterocentricity

In order to study the influence of the difference between the center of mass and shear center position of the main girder cross-section on the coupled vibration response of a vehicle–bridge, and in accordance with the theory of finite element analysis, we derive the stiffness matrix of the spatial girder unit with the main girder cross-section mass–shear center heterocentricity, use finite element software to establish a bridge model, select a three-axle heavy vehicle, and solve the coupled vibration equation of the vehicle–bridge by the separation method. A large-span self-anchored suspension bridge is taken as the research object, and a self-programming program is used to calculate and analyze the influence of the main girder cross-section mass–shear center heterocentricity, driving lanes, and speed on the coupled vibration response of the vehicle–bridge. The results show the following: the main girder cross-section mass–shear center heterocentricity has a significant effect on the transverse dynamic response of the bridge, and the peak values of transverse displacement and acceleration in the main span are increased by about 87% and 136%; the outward shift of lanes has a greater effect on the transverse dynamic response of the bridge; and the vibration response of the bridge while considering mass–shear center heterocentricity is more affected under different vehicle speeds.