Study On Performance Of Micro-perforated Absorber Based On Transfer Matrix Method

As a kind of resonant sound absorption structure,MPA(Micro-perforated Panel Absorber)has a wide application prospect in improving sound quality and reducing the influence of noise by wide band and high sound absorption.In order to evaluate the sound absorption characteristics of various sound absorption materials quickly and ensure consistency of evaluation.Metal microperforated panel absorbers are the best candidates for standard sound absorption samples because of their robust sound absorption performance.This paper focuses on the task of designing a standard MPA template which meets the requirements of broadband,high absorption and stable sound absorption performance.There are three main aspects in this paper:Firstly,on the basis of Dah-You Maa's classical theory of Micro-Perforated plates,basic acoustic units of MPA are analyzed,and the absorption structures of single-layer and double-layer perforated panels based on acoustic-electric analogy method are compared.The application of transfer matrix method in the absorption structure models of single-layer and double-layer perforated panels is emphatically summarized.The absorption performance of MPA is simulated by using MATLAB,showing effects of those parameters that are named as perforation diameter d,plate thickness t,perforation rate p,and cavity thickness D on the sound absorption performance are shown.Secondly,Orthogonal experiment of MPA sound absorption performance is carried out to explore whether there is interaction among above parameters by using transfer matrix method.Experimental analysis show that there is a significant interaction between structural parameters instead of a single factor alternation method.In this paper,genetic algorithm is used to optimize corresponding structure,selecting the effective sound absorption area and area ratio as the optimization objectives,and developing the optimized structural parameters of single-layer and double-layer micro-perforated plates.Thirdly,Aluminium steel is selected as the base material of MPA and laser drilling technology is used to prepare to make test sample.This experiments were carried out according to GB/T 18696.2.The experimental results show that absorption performance of test sample is consistent with results of theoretical model analysis.The results of theoretical simulation and experimental measurements can be shown that the double-layer perforated panel has more stable acoustic performance than the single-layer perforated panel,leading to experimental measurements are closer to the simulation values under the transfer matrix method,which owns sound absorption capacity of more than 0.6 at 1000-5000Hz.