Study On Spatial Coupling Dynamic Characteristics Of Vehicle-turnout In Linear Induction Motor Wheel/Rail Traffic System

The linear induction motor (LIM) wheel/rail traffic system is a new type of rail transit system, which stands for a comparatively new urban transit system. LIM wheel/rail traffic system, which has good capacity of gradeability and the adaptability to sharp curves, has already been applied in Japan, Canada, USA, Malaysia, China, and etc. Although a lot of research work has been carried out on the type selection of LIM and the spatial dynamic model of vehicle-track, the study on spatial coupling dynamic characteristics of vehicle-turnout in LIM wheel/rail traffic system is still inadequate.For the mechanical characteristics of turnout, there is great difference between the turnout of LIM wheel/rail traffic system and that of traditional wheel/rail system, so it is important to research on mutual adaptability of turnout and LIM system. In this thesis, taking Chinese No.9 Turnout (used in urban transit system) for example and based on the characteristics of LIM wheel/rail traffic system, the spatial coupling dynamic model of vehicle-turnout is established, including the dynamic model of vehicle, the dynamic model of turnout, the model of wheel-rail dynamic interaction and the model of the electromagnetic interaction between LIM and reaction plate (RP) on turnout. In this model, the vehicle, bogie, wheelset, LIM, rail and RP have been synthetically considered. In the model of turnout, the vibration of switch, connection section and frog of turnout is considered. The cross section variation of switch rail, movable point frog rail, the force transmission between jacking block and spacer block are also taken into account. In the model of interaction between LIM and RP on turnout, influence caused by discontinuity of RP is considered. According to the generalized energy-variation principle and the finite-element method, the differential equations of spatial coupling dynamic model of vehicle-turnout in LIM wheel/rail traffic system are established.In this thesis, coupling dynamic vibration characteristics of the LIM wheel/turnout traffic system is analyzed by computer simulation program of LVTSDSS , which is used by Newmark method and compiled by Fortran language.For the precision and stabilization of simulation program, the integral step length is confirmed and the appropriate span of parameters can be obtained by numerical test. Through the contrast between test results and existing analytic model, the stability of the results can be proved, and the rationality of the programs can be verified. Compared with traditional wheel/rail system, study is on the necessity of research and the specialty of dynamic characteristics of vehicle-turnout in LIM wheel/rail traffic system.Based on the above models and programs, according to the spatial coupling dynamic model of vehicle-turnout in LIM wheel/rail traffic, study is done on vibration characteristics of vehicle system and turnout system when the vehicle passing through the turnout branch and main. Research is done on the main designing parameters of vehicle system (different velocities, axle loads, suspension modes of LIM, and etc.) and the main designing parameters of turnout system (influence of stiffness under rail and layout of RP in turnout section, and etc.) in LIM wheel/rail traffic system.On account of the stability, comfort and security of vehicle operating, the research on mutual compatibility of turnout system is done, and the deep study on the LIM system and the rational, effective measures for vibration control in LIM wheel/rail traffic system is made by above models. In this thesis, the reasonable suggestions for design, construction and maintenance of turnout in LIM wheel/rail traffic system were putted forward. Accordingly, the research is a reference for the development of the LIM wheel/rail traffic system in china, and it is also important for control of gap and vibration control.