Amplification effect classification analysis on vehicle-bridge system under road surface random excitation

A classification analysis method on dynamic amplification effect of the vehicle-bridge system was proposed under random spectral excitations of the road surface. The differential equations of vehicle-bridge system were solved on numerical method. The dynamic amplification factor in system was calculated and geometrical significances of point, line and plane of the factor were endued. The roughness dynamic amplification factor was defined, and was calculated based on the classification of the response type, vehicle velocity, road surface roughness. Results show that the dynamic amplification effect increases with the vehicle velocity and the ranks of road roughness, and the amplification factors of bridge are always little than those of vehicle under different ranks of road roughness. The factors are significantly affected by the rank of road roughness. So the road maintenance should concentrate on reduction of impact of bridge and vibration of vehicle.