Research On Influence Of Wheel Polygon Phase On Vehicle System Vibration

With the rapid development of subway vehicle and the continuous increase of subway vehicle’s capacity,the wheel polygon wear phenomenon of subway vehicle is becoming increasingly serious,and the wheel polygon excitation will significantly increase the wheel-rail force,then transmitted upward to the bogie frame and car body,down to the ballast and track subgrade,seriously affecting the vehicle operation safety and vehicle ride comfort.Furthermore,the wheel polygon excitation with specific frequency may also cause the bogie frame resonance problem,which make it vibrate more strongly,and affect its fatigue life.The current research on wheel polygon mainly focuses on its wave depth and order,and there is less research on wheel polygon phase among four wheels of a bogie.In this paper,a rigid-flexible coupling vehicle system dynamic model is established based on a specific subway vehicle from our nation,subjected to wheel polygon excitation with different phase,and the influence of wheel polygon phase on vehicle system vibration is studied.The specific content is as follows:(1)A dynamic model of the vehicle system in which bogie frame is treat as flexible body while other body are not is established.Wheel polygon excitations with various frequency are applied to vehicle system dynamic model.The results show that when the wheel polygon excitation frequency is approximately equal to the 1st-order modal frequency,the bogie frame 1st-order modal resonance problem will occur.(2)On the basis that the bogie frame resonance problem has occurred,the effect of wheel polygon phase on the modal coordinate of the bogie frame is analyzed.The response of flexible body equals to the sum up of each modal coordinate multiplying its modal shape.The results show that when there is a phase difference between the wheel polygons in the diagonal position,the 1st-order modal resonance problem of the bogie frame is most severe.The more large the phase difference is,the more severe the resonance problem is.Therefore,the vibration acceleration of the bogie frame is much bigger in the out-phase wheel polygon case than the in-phase wheel polygon case.(3)The influence of wheel polygon phase on wheel-rail system and vehicle operation stability is analyzed.The results show that the wheel polygon excitation with phase difference will enlarge the amplitude of wheel rolling movement,but there is no obvious effect on the wheel-rail force.When there is a phase difference between the left and right wheel polygons,the acceleration of the car body is biggest.119 figures,13 tables,64 reference...