Dynamic Performance Study And Finite Element Analysis Of Resilient Wheelset

With the extensions of city scopes and the varieties of city developing modes, the public transport requires not only large quantity but also high quality. To ameliorate the public traffic problems, the perfect urban rail transport systems have been developed in many developed countries except the traditional road traffic, which have formed a solid urban rapid rail traffic network including ground, underground and over-ground. As an effective traffic, light rail transit has been widely adopted by many large cities in the world, and more than 10 cities in our country are planning or building the light rails in our country. To reduce noise, vibration and wheel/rail force, and improve ride comfort and fatigue life of wheel/rail, the resilient wheelset becomes the inevitable outcome of urban public traffic.The resilient wheelset has been widely used in light rail transit abroad, but it is in an initial phase domestically. There are very few publications on the resilient wheelset vehicle system dynamics and the nonlinear constants of the rubber that is used in wheelset. The present thesis makes a thorough research on the resilient wheelset structure, the selecting of the rubber nonlinear constants and vehicle system dynamics for the first time in our country. It provides the theoretical foundation for developing vehicle equipped with resilient wheelsets in China.Because the structure of the resilient wheelset is complicated and special, it is specially noticed that safety, maintenance and simplicity should be taken into account in selecting the structure type. In light of the situation of our country, it is unreasonable to blindly seek after new technology and developing direction. The ratio of its vertical stiffness to lateral stiffness is very important in structure design. Therefore, a few common and recent structure modes of the resilient wheelset abroad are described in detail in the thesis.The dynamic model of the vehicle-track vertical coupling system with resilient wheelsets is set up. 18 degrees of freedom are taken into consideration in the vehicle model, including bounce motions of carbody, bogie frame, axle and wheel, and pitch motions of carbody and bogie frame. On the basis of the above model, the differential equations of the coupling system are derived. By inputting impulsiveexcitation, the dynamic simulation of vertical wheel/rail force, wheel/rail contact stress and accelerations of axle and bogie frame for resilient wheelset system is carried out and the results are analyzed and compared with the system of rigid wheelset. In additions, the stiffness of rubber is optimized.In the finite element calculation of resilient wheelset, the general relation between rubber hardness and rubber mechanical constant symbolized by C1 and C2 is analyzed. Experiment method of C1 and C2 is presented, and the constants are determined. Stresses, deformations and modalities of the resilient wheelset are analyzed. The calculative results are compared with those of the rigid wheelset. Study on the influence of constitutive parameters of rubber on static strength of the resilient wheelset is also carried out.