Study On Wheelset Stability Based On Energy Coordinate System

High-speed rail has developed rapidly in the domestic and overseas, which had advantages of large transport capacity, low energy consumption, high safety performance. A lot of manpower, material and financial resources have been devoted to the high-speed rail, especially after the’One Belt And One Road’policy was put forward.However, with the continuous improvement of the train speed, aspects of vehicle performance have been demanded much higher. Among them, lateral movement of the vehicle stability is a very important issue. Hunting instability is a phenomenon peculiar to railway vehicles, which is the key to the vehicle lateral movement. How to solve critical speed meandering instability is the most critical of a series of vehicle system problems.Domestic and foreign scholars’study was based on linear model to define the critical speed of the vehicle. There were few studies considering nonlinear factor, especially in terms of theoretical analysis.In this paper, stability of lateral movement has been studied based on energy method. Energy coordinate was established, by which the energy coordinate transformation formula has been deduced to solve the critical speed of the wheelset motion equation.(1) Energy coordinate was established. And coordinate transformation formula from phase plane coordinate system to energy coordinate has been deduced. Further, stability criterion and the periodic Solutions approximate expression have been obtained.(2) Wheelset motion equations have been deduced considering the nonlinear characteristics of taper and primary suspension parameters.(3) Wheelset motion equation was put into the Energy coordinate and the transformation formula has been deduced. The critical speed expression has been obtained, with which the Routh-Hurwitz criterion was compared.(4) The taper was divided to three different expressions that increases, keeps constant and decreases as the increase of the lateral displacement. Effect of three cases the formula for the critical speed of the wheelset has been considered.(5) Primary suspension characteristics were divided into three, including soft elasticity,linear elasticity and hard elasticity, in which case the wheelset hunting critical speed was studied.