Mileage-evolution Of Bogie Noise And Vibration Of A 200km/h Train

In recent years,the high-speed EMUs have been developed on a large scale in China for its convenience,efficiency,safety and comfort.Under the long-term effects of abominable environment along the line,the polygonal wear of the wheels and their vibration noise become more and more serious along with their operation mileage increased.Serious wheel polygon wear can lead to high wheel-rail rolling impact,the fierce vibrations of vehicle-track system,and in severe cases will also endanger the safety of high-speed trains.That the wheel polygon wear states and vibration-noise characteristics under complex environment is difficult to describe accurately by current numerical methods.Therefore,it is necessary to carry out the tracking experiment so as to obtain the regularity of wheel polygon wear and vibration-noise characteristics,which can provide data support for simulation calculation.The main researches as follow have been carried out.(1)Based on the field test of the wheel roughness and vibration response,in the single reprofile period,the influences of the wheel polygon wear to the vibration-noise characteristics of the EMUs have been analyzed.The wheel polygon wear and the vibrationnoise characteristics of the wheels under different reprofile mileages are studied.The conclusions are as follows: during the third reprofile period,the wheel surface state is mainly represented by the wheel polygon wear of the 14~16 order,the amplitude increased with the operating mileage.The vibration and noise characteristics of the EMUs developed slowly within 50 thousand kilometers,and gradually increased within 5~ 150 thousand kilometers,that is mainly due to the development of 14~16 order wheel polygon wear.(2)Based on the field test of the wheel roughness and vibration response,In the complete tracking period,the influences of the wheel polygon wear to the vibration-noise characteristics of the EMUs have been analyzed.The conclusions are as follows: in the complete tracking period,the wheel surface state is mainly represented by the wheel polygon wear of the 14~16,20~23,25~27 order polygonal wear.The noise and vibration characteristics of the EMUs from the 4th to 6th reprofile periods are consistent with the third reprofile period,and it is different from the 7th and 8th periods.The main reason is that from the 7th period beginning,the EMUs operated in different lines.In addition,with the increase of operating mileage,wheel diameter may changes the order and development speed of wheel polygon wear.(3)In this paper,effect of thickness of the rim on wheel polygon wear and sound radiation of wheelset is studied based on the wheel roughness,vibration and noise tracking test of high-speed EMUs,and the simulation of the sound radiation of wheelset.The results show that,the vibration of the axle box increases less in the high frequency part due to rim becoming thin with the same wheel roughness.In addition,the change of rim thickness will affect the development of wheel polygon based on the ‘Principle of fixed frequency and equally divided wheel’.And the change of wheel polygon will further affect the vibration and sound radiation noise.(4)The effect of the season on the vibration and noise characteristics of the EMU is studied by the wheel roughness and vibration response tests in different seasons.The results show that with decreasing of the temperature,the natural frequency of vibration and the corresponding amplitude increases.In addition,seasonal changes will affect the development of wheel polygon wear,showing that the amplitude and speed of the development of polygonal wears in winter and spring is higher than that in summer.