Stiffness Transition Analysis of a Steel-Concrete Joint Section Based on Vehicle-Bridge Interaction

In order to study the dynamic stiffness transition issue of hybrid girder bridges, a vertical vehicle-bridge coupled vibration model was built for a cable-stayed bridge with single tower. In the coupled vibration model, a finite element model for the bridge was established by converting the joint section to the same material according to the equivalent stiffness law, a tri-axial vehicle model with 9 degrees of freedom (DOFs) was adopted, the sample of class B road roughness was simulated from the roughness spectrum in the national code by the trigonometric series method, and the motion equations of the coupled vehicle-bridge system were solved by Newmark-β method. According to the vehicle-bridge coupled vibration model, the dynamic analysis codes of the vehicle-bridge interaction were programmed to solve the system's dynamic responses under different conditions. The results show that the vertical acceleration of joint section will double if the road roughness decreases a grade; in dynamic behavior, the dynamic transition of the fully filled joint section is slightly smoother than that of the half filled.