Research On Transverse Vibration Problem For The Power Car Of Power Concentrated EMU

As one of the main ways of transportation in China,railway transportation plays an important role in economic development and people’s livelihood and welfare.Our country newly developed power concentrated EMU with a speed of 160 kilometers per hour,it has obvious advantages in economy and technology.However,when the power car driven at a speed of about 160km/h in the straight section,there is an obvious periodic fluctuation phenomenon in the lateral vibration acceleration of the car body.Therefore,it is necessary to analyze the causes of Transverse Vibration and proposed corrective measures of power car to optimize the quality of operation and improve transportation efficiency.In the thesis,taking the power car of power concentrated EMU as the research object,it occurred serious transverse vibration problem in the straight section,analyzed the phenomenon and proposed corrective measures.Through field investigation and simulation analysis,the limit value of rail grinding deviation is proposed to suppress the phenomenon of vibration,and the main research work and results are as follows:（1）The thesis conducted transverse vibration test of the power concentrated EMU,installed vibration acceleration sensors on the key components of the standard flange wheel and the thin flange wheel power car respectively,and collected the vibration data online.The test results showed that when the speed of the power car reached 160km/h,the lateral vibration of the thin flange wheel power car body in the straight section was obvious,the lateral vibration of the standard flange wheel power car body was slight,and the power car is more prone to transverse vibration when it under tail push-type operation.（2）The single-section dynamic model of power car,25T passenger car and control car was established in SIMPACK.The single car was marshaled by the coupler,and two longitudinal dynamic models of traction-type and tail push-type were established under the working condition of 1M8T short marshaling condition.The dynamic performance of power car under the simulation conditions of straight section,large radius curve and small radius curve under the two traction modes was compared,and it was found that the dynamic performance of the power car under the operation of the tail push-type was worse.（3）By analyzing the vibration data,the result showed that the abnormal vibration of the car body came from the wheelset.Using modal method analyzed,the result showed that when the equivalent conicity was less than 0.05 and the speed is greater than 140km/h,the frequency of snake and center roll of the car body is very close,which is easy to produce coupling resonance.And the damping ratio of the second-order snake movement of the car body is too small,which led to the divergence and instability of the snake vibration of the car body after being stimulated,which is easy to lead to the occurrence of vibration phenomenon.Through the simulation study of the transverse vibration boundary,the result showed that when the equivalent conicity was less than 0.043,the transverse vibration phenomenon of the power car was serious.（4）Through the on-site investigation of the rail of the transverse vibration section of the power car,the result showed that the grinding profile of the rail had a large negative deviation,which led to the transverse vibration problem of the power car,and the 60N-0.6～+0.6mm rail deviation profile is fitted to analyze its influence on the operation quality of power car.Wheel-rail matching showed that when the rail grinding deviation is negative,the wheel-rail contact points moved to the middle of the wheel tread and the middle of the rail head,resulting in a small equivalent concity of wheel-rail contact and causing transverse vibration problem.When rail profile of 0.6mm maximum negative deviation and the wheel profiles of different measured JM₃were matching,the result showed that when the wheel tread concity is less than 41‰,the transverse vibration problem of car body occurred.The wheel profiles which occured transverse vibrate and the different grinding deviation profiles of the rail were selected for dynamic simulation,the deviation limit of the power car under the symmetrical grinding and asymmetric grinding conditions of the rail was obtained as+0.1mm～+0.6mm.（5）Based on the rail grinding silhouette deviation limit obtained by suppressing the transverse vibration of the power car,the adaptability study was carried out about whether the power car,25T passenger car and HXD3D electric locomotive occurred transverse vibration problem in the early stage of service,and whether there was shaking and structural snake instability in the late service of the car and rail,finally the deviation value of the 60N rail polishing profile should be controlled at+0.1～+0.3mm.Therefore,the railway department put forward the suggestions for rail polishing and carried out the test of power car addition,the test results showed that the transverse vibration phenomenon of power car is suppressed.In this thesis,the mechanism and boundary conditions that the power car occurred transverse vibrate were obtained by two research methods:test and simulation.The rectification and adaptability analysis of the transverse vibration problem was carried out from the rail grinding deviation,the results showed that when the grinding deviation value of 60N rail is controlled at+0.1～+0.3mm,the transverse vibration phenomenon of the power car disappears without causing other problem of other cars on the track.