Parameter Design And Optimization Of Multilayer Microperforated Panel Sound Absorption Material

The accurate measurement of sound absorption coefficient is the basic prerequisite for evaluating the quality of sound absorbing materials.In order to improve the accuracy and reliability of the measured value of sound absorption materials,it is necessary to establish the acoustic standard sample,the standard measurement method and the traceability approach of the measured material,so as to realize the quantitative evaluation of the acoustic characteristics of the sound absorbing material.In view of the lack of acoustic standard template in the measurement of sound absorption coefficient,this paper proposes a standard template of multilayer structure fabricated by metal micro perforated panel.The parameter design of multilayer microperforated panel sound-absorbing material is mainly studied.According to the design requirements of the acoustic standard sample plate,a metal plate with stable structure,convenient preservation and good sound absorption performance is optimized.Three models are established by genetic algorithm to optimize the parameters of the micro perforated plate.The aluminum micro perforated plate was successfully manufactured by laser drilling technique,and the sound absorption coefficient was measured in the acoustic impedance tube.The results show that the measured value can match the theoretical model well.The specific research contents include:First,According to the basic theory of Ma Dayou's microperforated plate,the equivalent circuit diagram of single and double layer microperforated plates is deduced by the class of acoustic electric analogy,which lays a theoretical foundation for the optimization of the standard plate.Second,using the genetic algorithm to design three models,the mean-variance method,the area ratio method and the area maximum method,which optimizes the parameters of single layer and double layer micro perforated plate.The optimized sound absorption coefficient and the frequency curve are compared and analyzed,confirms that after the optimization of the maximum area method,the parameters of monolayer and bilayer are the best.Third,the acoustic standard sample is manufactured according to the optimization results,and the acoustic performance is measured by impedance tube method.The results show that the acoustic performance of the standard acoustic model can well match its theoretical model.From the experimental results and the simulation results,the double-layer microperforated plate has more stable acoustic performance than the single layer microperforated plate.It can satisfy the design requirements as an acoustic standard template,and analyzing the uncertainty and the error of the experimental results at the same time,which proves the stability and reliability of the measurement system.