Vector Hydrophone Cepstrum Analysis Of The Material Reflection Coefficient Measurement Method

With the progress of science technology and the development of the society, theabsorption material has got a wide range of applications when the noise pollution is seriousnowadays. The Characterization of acoustic reflection coefficient is an importantcharacteristic of sound-absorbing material parameter. It makes the sound absorptionproperties to be quantified and provides a theoretical basis for the proper application ofsound-absorbing material. Therefore, how to effectively get the reflection coefficient ofacoustic materials becomes the focus of people research object.This article is mainly based on power cepstrum analysis to measure the reflectioncoefficient of the large sample of acoustical material in the free field. First described thespectrum analysis of the relevant theory, followed by given the power cepstrum of the basicprinciples to measure the reflection coefficient of acoustic materials and accomplish theformula derivation. Then discuss the formula of the reflection coefficient based on soundpressure, the numerical simulation and analysis of different signal, different distance from thetested baffle to hydrophone, different signal-to-noise ratio on the influence of themeasurement results.This paper also lays emphasis on the research of the cepstrum analysis method based onvector underwater acoustic materials measurement of reflection coefficient. Last discuss thebroadband narrow pulse method. Accomplish the formula derivation and simulations aboutpower cepstrum analysis based on sound pressure joint velocity and based on only velocity tomeasure the reflection coefficient of acoustic materials. By simulation analysis, this methodcan be feasible. And compared the sound pressure and based on the method based on vector, itis concluded that the method based on vector is more outstanding. Also discussed thebroadband narrow pulse method, this paper expounds the related theory of it and itssimulation. The simulation shows that Broadband narrow pulse method can find the effectivetime domain in pulse compression, in the frequency domain to expand the bandwidth of thelow frequency. The new method can avoid the diffraction wave and be helpful for the lowfrequency test.Based on the cepstrum analysis method to measure reflection coefficient of experiments,the results show that the measuring cepstrum analysis method based on sound overwhelm thereflection coefficient result than the average error based on the cepstrum analysis vibratingvelocity measurement of reflection coefficient; Both the mono-frequency signal and linear frequency modulation signal can get the right experimental results. Based on the soundpressure cepstrum method and only velocity cepstrum method, measurement results hasnothing to do with hydrophone sensitivity, so compared to other method, this method cansimplify the experimental process.