| Rail wave wear is a kind of rail wear phenomenon widely existing in railway line.With the increase of axle load and train speed,almost all railway management departments are suffering from railway damage,which not only affects the dynamic characteristics of the locomotive,but also reduces the service life of the track,produces noise nuisance and increases the maintenance cost.Therefore,it is of great practical value to carry out in-depth research on the influence of rail wave wear on locomotive dynamics and the cause of wave wear.In this paper,a wide-rail heavy-duty locomotive is taken as the research object,the vehicle dynamics model is established,and the locomotive dynamic performance evaluation index and wheel-rail wear index are selected to analyze the locomotive system maintenance mode.The numerical model of rail wave wear was established,and the numerical simulation of rail wave wear was carried out using MATLAB software.The rail wave wear was superimposed into the vertical component of the five-order spectrum as track excitation.The critical speed and wave grinding excitation frequency were calculated.Based on the theory of vehicle dynamics,the influence of rail wave wear on locomotive dynamic performance and the influence factors of rail wave wear were analyzed.The following conclusions are obtained:(1)Under different working conditions of wave grinding,the critical speed of the locomotive is between 252～254km/h,and the generation of wave grinding has almost no effect on the critical speed.The difference between the conditions with wave grinding and no wave grinding is within 2km/h.(2)When the speed is lower than 80 km/h and the wavelength is larger than 450 mm,the excitation frequency of the wave grinding is close to the natural frequency of the wheel set and motor,and it is easy to resonance,and the vertical force and vibration acceleration of the wheel and rail increase obviously.Linear wave grinding has little effect on the transverse dynamic performance of locomotive.(3)The running speed of locomotive in linear condition and the setting of rail bottom slope have different degrees of influence on rail wear,among which the running speed has a greater influence.Therefore,reasonable passing speed and rail bottom slope size should be set according to the actual axle load of vehicle.(4)The influence of wave grinding on curve lines on vertical vehicle dynamics is more serious than that on linear lines.Under the condition of wavelength greater than 400 mm,the vertical wheel-rail force exceeds the limit value in all cases,and the vertical wheel-rail force changes the most at the speed of 50 km/h.The speed of the locomotive is lower,and the excitation frequency of wave grinding is closer to the natural frequency of the locomotive,which is more prone to resonance.The influence of wave grinding on vertical Sperling index of car body is obvious,and the change of vibration acceleration of car body is obvious.When the locomotive passes on the curve line,under the influence of centrifugal force,the weight of wheels on both sides is different.The appearance of wave wear will increase the vibtation amplitude of wheels and the wheel-rail vertical force.The load reduction rate of wheel weight and the derailment resistance coefficient will decrease,which can seriously affect the operation safety of the locomotive.(5)The passing radius and passing speed of locomotive in curve condition have great influence on wheel-rail wear.The wheel-rail creep force change and transverse force change are obvious.The influence of ultra-high curve on wheel-rail wear is small.Therefore,in the practical running lines,the appropriate curve radius should be set to match its passing speed,and the setting of ultra-high curve,the setting of rail bottom slope and the actual running number should be considered comprehensively.The friction between wheel and rail can be reduced to the greatest extent,thus reducing the formation speed of rail wave wear. |
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