Research On The Influence Of Wheel Polygonization On High-speed Vehicle System

With fast running speed and large transporation quantity of high speed railway,which develop wheel wear because of wheel/rail interaction caused by long term running,significant harmonic order polygon wear can be found from some wear wheels.Wheel polygonization can directly change wheel/rail contact geometry relationship,and therefore it even influences vehicle track vibration characteristics.Wheel polygonization is no more than deteriorating the performance of vehicle dynamic,and has an important impact on the train operation safty and comfort even seriously influence performance of each component.On the other hand,vehicle/track coupling dynamics and polygon wheelset lead to resonation,which also aggravates wheel wear formation and development.A new wheel polygonization mathematical model is built according to the actual date in this paper,the vehicle/track coupling dynamics model considering wheel polygonization is established based on the vehicle/track dynamics and wheel/rail relationship theory,a whole vehicle is taken as the research object,the numerical simulation is made applying dynamic software SIMPACK.In case of without either wheel eccentricity or track excitation,the research on the influence of wheel polygonization on vehicle/track system dynamics behavior is carried out.Numerical analysis and conclusions are as follows:The vertical comfort of the car body is lower than that of the lateral comfort,it is sensitive to the result of low order polygon of car body comfort.On the assumption that velocity and the order of polygonization keep constant,travelling comfort result double increase with polygon non-circular degree from 0.1mm to 1mm,comfort does not meet the comfort index at the critical speed.Numbers of the order of polygon wheel that given by maximum value of comfort when the railway is operating in the speed of 200?310km/h can be regarded as an engineering reference.In terms of studying the effect of wheel polygonization on vehicle safety,derailment coefficient is unaffected with the speed of vehicle within the critical speed.Wheel/rail force will increase along with polygon wheel order,out-of-roundness degree and running speed,the 6th order polygon wheel begins to appear rail jump,the 7th order polygon of whee/rail force reaches safety limits and the 11th order polygon wheel will produce great dynamic wheel/rail impact force,and seriously rise to the impact load limit.According to the safety standard of the vehicle running dynamics,the critical wheel out-of-roundness degree is determined under the speed of 200?310km/h and the polygon order of 2?20.So it can provide theoretical guidance for the out-of-round operation limit of high-speed railway and wheel repair cycle.The 3th order wheel polygonization on the condition many kinds of phase angle difference under the speed of 250km/h are taken as an example,the effect of vehicle safety and comfort are,The maximum of wheel/rail force are studied,The worse case of affecting wheel/rail force,wheelset lateral displacement and vertical comfort are obtained,which has a certain engineering refrences value for the safe and reliable operation and monitor of vehicles running.