Dynamic Response Analysis Of Highway Concrete Simply Supported Beam Bridges With Damage Under Moving Vehicles

The former research on the coupling vibration between vehicles and bridge has been majored in the vehicle load form, the changing effect on the dynamic response of the bridge by the bridge deck geometric features, the dynamic response between vehicles and the bridge by the earthquake or the wind load. Nonetheless, there is no indepth research in the influence rule between the various bridge damages and the dynamic performance of the bridge under the vehicle load, and the interaction mechanism between structural damages, the damage evolution and the dynamic behaviors between vehicles and the bridge. The basic research is urgent to be carried out. In the process of bridge operation, the coupling effect of a damaged bridge and vehicle load has become one of the important factors of bridge safe operation. This paper focuses on the analysis and research of the dynamic response of a damaged bridge under the vehicle load.Based on the investigation and classification of the traffic load, various space vehicle models are established respectively and all kinds of vehicle motion equation are derived by Lagrange equations, which results into the fact that the dynamic analysis model of vehicles is improved increasingly. On the basis of multistage structure theory and component mode synthesis method, a multi-scale analysis method and calculation model with high efficiency and high precision is established, which can reflect the dynamic behaviors of local details and the overall of a concrete simple bridge. In the end, the method is subjected to a program verification, including the analysis and calculation by ANSYS, the adopted LS-DYNA of a simple beam bridge by MATLAB, and the dynamic test of a real precast hollow slab concrete beam bridge.According to the old bridge test data with a long-term accumulation, combining with the relevant data and literatures at home and abroad research, the system analyzes the production mechanism and the processing characteristics of all kinds of the typical damage in concrete bridges, classifies the bridge damage, conducts a conclusion and comparison of the various bridge damage simulation strategies and methods, raises and constructs a numerical analysis model of the coupling vibration for vehicles and bridge for concrete bridge damage. On the basis of the damage simulation and the coupling vibration of vehiclesand bridge multi-scale analysis method, the damage model is introduced into the multi-scale analysis model of the bridge for various damage types and states. Meanwhile, by the activation and modification for structural damage parameters, a multi-scale analysis method as well as the analysis of the relevant procedures for the coupling vibration of vehicles and a concrete bridge, which contains a single damage and multiple damage, is established. For example to a precast hollow slab concrete beam bridge in the domestic, the dynamic response of this bridge is analyzed in the situation of damage. In addition, on the point of the dynamic analysis, a theoretical basis for the researches on the load limit and speed limit of a damaged concrete beam bridge at present is offered.