| The development of urban rail transportation in China has entered into a period of rapid development. Since a large number of rail vehicles pass through underground tunnels, the problem of coupled dynamic response of rail vehicle/tunnel has drawn more and more persons'attention. On the one hand, dynamic impact on the tunnel brought by the high-speed passing vehicles will cause a structural fatigue of the tunnel, and reduce its strength and stability. On the other hand, the coupled vibration of vehicle/tunnel affects safety and stability of vehicles. Therefore, it is necessary to study on the dynamic response characteristics of the rail vehicle and the tunnel. Based on the 3D non-linear modeling method and parallel computing techniques, this paper presents the study on the numerical simulation of the coupled vibration of rail vehicle/tunnel. Main work of this paper is as followed:The basic theory of the numerical simulation of the couple vibration of rail vehicle/tunnel is studied. Considering the geometric nonlinear of the large tunnel structure and the dynamic interaction between vehicle and tunnel, from the point view of numerical analysis, geometric nonlinear analysis method and numerical method for the dynamic contact are studied, which provide theoretical basis for solving the problem of the dynamic response of the couple vibration of rail vehicle/tunnel. Explicit Central Difference Algorithm is applied to solve the geometric nonlinear FEM equation. The contact search method based on segment and symmetric penalty function method is used for various contact relationship. Based on the characteristics of the rail vehicle running and on the structure of DAWNIING 5000A supercomputer located in Shanghai Supercomputer Center, the domain decomposition method for parallel computing is used.The modeling technology of the full three-dimensional nonlinear refined finite element models of the large tunnel and rail vehicle is studied. Based on the virtual modeling technology, and with sufficient consideration to the actual structure of tunnels, the finite element model of tunnel, which contains tunnel lining, cross-passage, deformation joint, inner lane plate, bracket and track bed, is built up. After stratification by actual geological data, and with the consideration of the impact of external water pressure, soil is simulated by elastic-plastic material of D-P. Vehicle model is composed of wheel, bogie, secondary suspension structure and car body. Coupling of penalty function is used to simulate the interaction of wheel-rail, rail-tunnel and tunnel-soil.The initial working condition, that is, the deformation and stress analysis of the main tunnel and cross-passage under the function of gravity and water pressure is studied. The initial form of tunnel in the non-operating state is simulated. The influencing factors of the initial form, such as depth, water pressure, the axis of tunnel and connecting passage are analyzed. Additionally, the initial condition also provides prerequisite for other conditions.The coupled vibration without initial stress is studied. The variation law and influencing factors of coupling vibration of the tunnel structure and the rail vehicle cause by rail moving load, rail roughness and road traffic flow load in the process of running rail vehicle. In this condition, the coupling relationship of rail vehicle/tunnel is clearer presented.Coupling vibration under the condition of initial stress, which could truly reflect the deformation and stress distribution of the tunnel structure, is studied. Based on the results of that initial condition, the dynamic response of tunnel structure under the load of rail vehicle and road traffic is calculated objectively and accurately. The maximum dynamic displacement, deformation and stress of the tunnel structure in the coupled vibration is calculated, in order to check whether the tunnel structure meet the design requirements, which provides theoretical basis and reference data for optimizing design of the structure of tunnels.
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