Mechanism Study Of Wheel Polygonization Based On Modal Analysis Of Rail

A detailed investigation conducted into the mechanism of the polygonal wear of EMU train wheels is presented through extensive dynamic experiment.This paper summarizes the typical vibration characteristics,time-frequency domain transmission relationship,and the evolution and development of polygon wear.The dynamic model of the track including the rubber gasket,the fastener and the rail is established.Considering the constraint effect of the two bogies on the rails,the modal vibration characteristics of the rail are analyzed.The excitation conditions of the rail mode are studied,and the frequency components directly related to the frequency of the polygonal wear of the wheel are analyzed.The frequency source of the wheel polygon problem is determined.The relationship between the relative vibration frequency,wheel rotation frequency and wheel polygon frequency is established.The conclusions as follows:1)Polygon vibrations are transmitted through track.The vibration energy of axle box will be enlarged obviously as the frequency is different between two wheelsets.The high-frequency vibration will be transmitted to the non-polygon wear wheelset.2)The wheel polygonization high frequency vibration is developing rapidly in the short time of the wear circle.3)The modal vibration characteristics of the rails are calculated by the theory of the Timoshenko and the finite element method.The third order vertical bending mode frequency coincides with the polygon frequency.4)Combining the relative vibration frequency,wheel rotation frequency,polygon order,wheel-rail contact regeneration flutter model and forced regeneration flutter model can be used to describe the formation mechanism of wheel polygons without initial non-round and the development mechanism of wheel polygonization.