Effects Of Wheel-Rail Contact Dynamics On Non-Circular Of High-Speed Traiwheels

With the rapid development of China’s high-speed railway and the continuous improvement of the speed of high-speed trains, China has built the world’s largest and highest operating speed of the high-speed railway network. To 2015 of second half, the railway traffic mileage of China has reached 12.3 million km, including high-speed 1.9 million kilometers and the speed of 200-250 km/h of 1.13 million kilometers, speed of 300-350 km/h of 0.67 million kilometers, almost coveraging of the city of more than 50 million of China’s population. With the improvement of the speed of the train operation, some problems can be ignored before are becoming prominent, high speed train wheel wear leads to the non-circle is one of them.The uneven wear of wheel pair leads to the appearance of the wheel tread is not rounded, and the shape of the wheel is changed, which leads to the change of wheel/rail contact geometry. The wheel/rail contact geometry is the core of the vehicle running, and it is also the key factor that affects the safe operation of the wheel/rail, and the wheel/rail contact geometry has a great influence on the running quality of the high-speed train.According to the parameters of the EMU CRH2 car corresponding high speed train vehicle dynamics model was established by using multi-body dynamics software universal mechanism. Setting different speeds,axle load and friction coefficient are in the model, and run 12 s on straight rail. The wheel/rail contact vibration characteristics under different speeds are calculated.The results show that: Wheel set in motion process, the wheel rail vertical to force versus time curves can approximate changes periodically with a period of about 0.1 s; maximum vertical force for 115751.8N, minimum 688.4N, respectively is static loading between wheel and rail of 193.8 times and 0.012 times; round corner opposed the vibration period of T=0.05 s, the maximum vibration amplitude for 1.568 mrad; transverse vibration cycle T=0.95 s, amplitude is 3.3mm.The initial condition of the finite element calculation is to choose the position contact parameters of a certain moment. To the EMU CRH2 LMA wheelsets and CHN60 rail as the analysis object, through the finite element software ABAQUS to establish large-scale finite element model, the mixed Lagrangian Eulerian method is adopted to establish the high-speed train wheel-rail rolling contact transient model. The general rules of creep and wear of wheel are obtained by calculating results. The results show that: under the vibration behavior of the wheel/rail, wheel/rail contact positions and longitudinal creep sliding force change time by time; the bigger wheelset lateral displacement and the wheel/rail normal force and the greater wheel/rail contact patch inside longitudinal and lateral creep force is, then the more serious wear, resulting in wheel of non-circular of wear. Wheel tread wear surface periodic law by the coupling effect of the periodic change of the wheelset lateral displacement and the wheel/rail force cycle changes, this is the wheel tread complex multistage wear the root cause.