The Study Of Dynamic Characteristics Of Longitudinal Connected Ballastless Track On Bridge And Flaws Detection By Its Dynamic Characteristics

Over the past10years, China has invested heavily in high-speed railway research and construction. As China’s main form of high-speed railway track structure, non-ballast track on bridge needs more dynamic analyses, focusing on studying the vehicle-bridge-rail system vibration characteristics and classifying sensitive vibration frequencies of its various parts, from which researches can be done on the impacts and diseases caused by vibration on the vehicle-bridge-rail system, such as the damages of track structure, rail corrugation and disease detection based on the frequency domain analysis. With these analyses, the railway projects’designing, operation and maintenance can be guided, which helps reduce the impacts of various diseases.Taking into account the feasibility, workload issues and the above reasons, this paper founds a reasonable vehicle-track-bridge model, by analyzing its basic dynamic parameters combined with the practical problems in railway projects, mainly studies on the natural vibration characteristics of the system, such as the vibration form of each part and its interrelationship, thus obtains the sensitive frequencies range of each part of the coupled system. The author hopes that this paper can make contributions to further research work.Finally, this paper does some exploratory studies on modal analysis, taking the strain mode theory into flaws detection in railway engineering. The results show that strain mode technology does well in the detection of the base plate and board local flaw, both on the location and the extent of the flaw; what is more, it is of high sensitivity.