| At present, a large amount of bridges, mainly middle & small concrete bridges, has been made in our country. These bridges suffer from a lot of unfavorable environmental factors and mismanagement impact, which inevitably result into a variety of injuries. However, the current situation of SMC bridges in our country is still not paid enough attention, while the bridge evaluation methods are still in a relatively backward stage. In this paper, to achieve a fast and effective detection, a method of bridge damage identification, based on vehicle-bridge coupled vibration method, is established. It will hopefully reduce overall maintenance costs, ensure the performance and the operational safety of the structures, which means a lot of social value and economic significance.The vehicle’s motion equation is derived by the Lagrange equation, with the matrix of mass, stiffness and damp. Starting with the typical model of a moving mass with a spring, a coupled vibration equation of 12-DOF vehicle and full-scale bridge structure is derived and established. A coupled vibration application for the damage simulation under different roughness and velocity with the method of Newmark- b is prepared.By a large amount of discussion about the origins of the typical bridge damage, choosing a reasonable way for the typical bridge damage simulation by ANSYS and proceeding the coupled vibration program to receive the response information. After all, a regular pattern of the structural response data from the damaged bridges is analyzed.Taking an RC beam bridge and a Hollow Prefabricated girder as the research object, the extracted acceleration response is used to be the original data for the process of the detection. By the EMD, the signal is divided into different levels of instinct mode functions(IMFs). Then, the signal is reunited to the process of a time-frequency envelope analysis and Hilbert spectrum analysis, which is a comparison method between the undamaged and damaged bridges. |
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