Vehicle Load-Induced Dynamic Performance of FRP Slab Bridges

The present study analyzes the bridge-vehicle interaction based on a three dimensional vehicle-bridge coupled model. Vehicles are idealized as a combination of a number of rigid bodies connected by a series of springs and dampers. The study is focused on a slab bridge that is modeled using finite element method to predict the modal characteristics. The bridge and vehicle systems are then integrated into a bridge-vehicle system based on deformation compatibility. Due to the complexity of the FRP sandwich panel, the finite element analysis is based on an equivalent solid plate developed by the authors. The response of the bridge is obtained in the time domain by using an iterative procedure employed at each time step, considering the roughness of the deck as a vertical excitation to the vehicles. The results of bridge dynamic response and the calculated impact factors of vehicle loads are compared between the FRP and concrete slab bridges. Finally, the applicability of the AASHTO impact factors (or called dynamic allowance) to FRP bridges is discussed.