The Method Of Vibration And Noise Transfer Path Analysis Based On Time Domain Iterative Algorithm

With the rapid development of high speed train industry in recent years,its high efficiency and convenience have greatly promoted social progress and economic prosperity.But at the same time,it is accompanied by more and more serious vibration and noise pollution.During the running of high speed train,the high decibels noise not only affects the comfort of the train,but also endangers the health of the passengers and the train attendants.At the same time,the violent vibration of the car body and the equipment under the train will also threaten the safety of the train.Therefore,it is very important to study the vibration and noise of high speed train and take effective measures to reduce the vibration and noise.There are many techniques to study the vibration noise of high-speed train,among which the most widely used is the transfer path analysis.The transfer path analysis is mainly divided into the traditional path analysis(TPA),operational transfer path analysis technique(OTPA),mixed transfer path analysis(OPAX).In this paper,the three methods are introduced,and the application of OTPA in real train is analyzed.The main transfer paths of vibration and noise of trains in low speed to high speed is analyzed,and the contribution of its transfer paths is solved.However,the analysis results of the OTPA method is wrong when dealing with short-time transient state data.Therefore,the iterative algorithm of the transfer function in the time domain is studied to compensate for the limitation of the OTPA method.Then in two aspects,single input single output system and multi-input single output system,the time domain iterative algorithm theory are described in detail.The rationality of the time domain iterative algorithm is also analyzed.Finally,three transmission systems are designed,the acoustic system,the vibration system and the acoustic vibration system,to verify the time domain iterative algorithm.The noise signal and vibration signal of the sample is normalized in the analysis of acoustic vibration system,and the normalized coefficient of vibration and noise is calculated.The final experimental results show that the application of the time domain iterative algorithm is completely feasible in short transient state,and the experimental analysis result conforms to the actual situation.This means that the method effectively compensates the defects of the existing OTPA technology in the analysis of transient conditions,and is another supplement for the method of transfer path analysis.