Research On Evolution Law Of CRH380B High-speed Train Service Noise

With the rapid development of high-speed rail,the transit time between cities has become shorter and shorter,and high-speed rail has become the preferred tool for more and more people to travel.Therefore,the safety and comfort of high-speed rail becomes particularly important.With the large-scale construction and operation of high-speed railways,the problem of internal and external noise effects of EMUs has become increasingly prominent.Noise control for high-speed railway is a systematic project.Although there are many noise issues in China,the projects are relatively scattered and lack systematization.There are many research units and low degree of openness of research results.Many units have repeated work during the research process.Therefore,it is urgent to carry out retrospective analysis and research on noise control of high-speed railways,establish a domestic database of scientific research results on railway noise,use existing research results to guide the current noise reduction work of high-speed railways,and at the same time find existing problems and deficiencies.Systematically carry out project research and provide corresponding countermeasures to provide a basis.This paper takes a CRH380 B EMU serving passenger passenger line as the research object for long-term follow-up testing,mainly testing various information such as wheels,noise and pantograph status.First,it studies the external roadbed,roadbed curve and bridge section radiated noise The overall development trend of the vehicle,as well as the analysis of the impact of wheel roughness and pantograph on the outside noise of the car;then study the overall development trend of the first and middle-class cars,pantograph,non-pantograph car interior end and middle noise,And the analysis of the influence of wheel roughness and door status on interior noise,and the analysis of the impact of pantograph vehicle status on the interior noise of the vehicle,including the lifting bow,the direction of pantograph opening and the contact force of the pantograph;the final analysis The general development trend of interior and exterior noise and the effect of wheel roughness on interior and exterior noise.At the same time,the comparison of interior and exterior noise before and after advanced repair was analyzed.The research shows that the noise level of the roadbed curve and roadbed section outside the vehicle is higher than that of the bridge as a whole;the noise at the end of the vehicle is 1 ? 5d B(A)higher than the middle;The bottom is located at a frequency of about 200 to 315 Hz;while the internal noise spectrum curve has a similar characteristic frequency(about 630 Hz)in the frequency range of 500 to 800 Hz,and a lower characteristic frequency of 125 Hz appears.After repair,the maximum amplitude of wheel roughness does not exceed 5.5d B,which can be reduced by 3d B / ?m ? 11 d B / ?m compared to before repair.The change of wheel roughness has a relatively obvious influence on the noise level inside the car and its energy at low and medium frequencies(80 ? 800Hz).For the noise outside the car,the energy in the characteristic frequency range of 500 ? 800 Hz has been reduced.Noise has all decreased,but compared to the pre-repair,the main characteristic frequency peaks of the spectrum have not changed.The noise in the passenger compartment of the EMU is 2 d B(A)higher than that of the bow when the bow is lowered.The end door in the compartment is 0 ? 4.6 d B(A)higher than the end and middle part in the closed condition.The closed state has a significant impact on the spectral characteristics of the noise at the end of the guest room,especially in the mid-to-high-frequency noise above 200 Hz ? 800 Hz,the open-door operating conditions are significantly higher than the closed-door operating conditions.The research and analysis of this paper show that the change in the contact force of the pantograph and pantograph network has little effect on the noise of the EMU during operation,and the wheel roughness has a greater effect on the noise inside and outside the car.