Analytical formulation and dynamic response investigation of a 3D vehicle-pavement-bridge coupled system

The three-dimensional vehicle-pavement-bridge coupled system (3D-VPBS) exhibits significant coupling and time-varying characteristics. Constructing a refined vehicle-bridge coupled system model is crucial for enhancing the accuracy of dynamic interaction simulations between vehicles and bridges. In this study, an analytical model of the 3D-VPBS is developed to investigate its dynamic response. A two-axle full-vehicle model with seven degrees of freedom is adopted to represent the vehicle, the bridge is modeled as a simply supported Kirchhoff plate, and the pavement layer is characterized by a continuous distribution of springs and dampers. The vehicle’s suspension and wheel systems are modeled using spring-damper elements, and the connection between the bridge and pavement layer is also represented by spring-damper components. Correlated left- and right-wheel road surface irregularities are introduced as external excitations to the system. The equations of motion are derived using D’Alembert’s principle and Kirchhoff plate theory and solved numerically via the Newmark-β method. Based on the proposed model, the effects of pavement layer properties, vehicle speed, traffic lane position, and road surface roughness on the dynamic behavior of the 3D-VPBS are systematically analyzed. The results indicate that incorporating the pavement layer effectively reduces the dynamic response of the vehicle body and enhances ride comfort. An increase in vehicle speed leads to intensified system responses and deteriorated ride quality. The traffic lane position has an impact on the partial dynamic responses of the system, with the maximum vibration occurring when the vehicle travels along the driving lane. Additionally, road surface roughness has a pronounced effect on vehicle dynamics, with deteriorating surface conditions resulting in amplified vehicle responses and reduced ride comfort.