Research On Forward Design Method Of High-speed Train Interior Noise

In recent years,great progress has been made in the cause of high-speed railway in our country.With the continuous improvement of operation speed,the requirements for vibration and noise are also constantly increasing.At present,the research on the vibration and noise of high-speed railways in our country is still in the stage of noise value control.The existing high-speed trains basically meet the design requirements under the current operating speed.However,if increasing the operating speed,the noise in the vehicle will definitely exceed the design requirements.The work is to constantly modify the body structure until the noise meets the requirements.Therefore,this article will study EMU interior noise design method,and the purposes is to obtain the vehicle body parts acoustic parameters that meet the design requirements before the production of vehicles and provide basic guidance for the actual engineering.Firstly,measuring existing EMU static acoustic parameters of the field,mainly include reverberation time and sound insulation volume measurement,and study the different principles of different measurement methods and selected reverberation time method for reverberation test and sound intensity method for sound insulation test according to vehicle site conditions,and finally evaluate the sound insulation volume use Rw.Carrying out the measurement of the existing EMU to obtain the vibration and noise interior and exterior the vehicle under the operating conditions.In order to clarify the effect of the main vibration excitation of the vehicle body on the floor outside the vehicle,we used hammer hammering method to obtain the vibration transmission relationship between air spring and vehicle floor outside.Aiming at the problem that the physical quantities of vibration acceleration and sound pressure is not uniform,the sound and vibration normalization is studied by the way that the sound power of radiation is equal through the aluminum alloy profiles are respectively excited by vibration and sound.Then,the interior cavity are reasonably divided into several sub-cavities according to the principle of statistical energy analysis and actual vehicle structure;the relationship between the exterior excitation source and the input power of the subsonic field is studied according to the theory of sound insulation.The SEA model factor and other parameters were studied theoretically and the necessary parameters in the SEA model were calculated based on the experimental data and model parameters.Based on this,a SEA model of the relationship between interior noise and exterior vibration noise was established.Correctness of the SEA model was verified and the result shows that the error of interior noise is within the allowable range between predicted and measured,the SEA model is true and reliable.Finally,the external vibration noise of the vehicle is recursively obtained under 400Km/h operation by using the actual measurement results of the EMU,and the interior noise is calculated by using the statistical analysis model.The calculation result exceeds the design standard,corrected the forecast results into the power flow equation to obtain the sound field input power.According to the principle of equal radiation,allocate the sound insulation volume.The results of sound insulation volume reallocated is more reasonable.This thesis can design the EMU acoustic parameters before the production of vehicles,which is the main innovation of this thesis,and has important engineering practical significance.