Research On The Experiment Of Sound Absorption Performance Of Micro Perforated Standard Acoustic Model

MPA is a resonance sound absorption structure that made up of perforation diameter under 1 mm and a cavity behind. The tests on sound absorption characteristics of materials have no quantity traceability system and the result incomparability. This topic main research content is to design the structure parameters of MPA, making standard micro perforation model, and test the sound absorption coefficient. Based on the theory of MPA which is proposed by M, sound absorption performances are researched by using MATLAB. By this means, the influence of the different parameters on the sound absorption performance are discovered. And MPA samples are fabricated by taking typical parameters for international standard impedance tube size. The frequency ranges from 100 Hz to 5000 Hz. The sound absorption performances of these samples are tested and analyze the experimental result and theoretical result. The thesis mainly completed the four aspects of content.Firstly, according to the theory of micro perforated panel requirement and the actual need to meet sound absorption performance to design the standards absorption model. The classical theory model of MPA developed by M is summarized. Taking into account the limitations of the processing conditions, select the appropriate combination of structural parameters to design standards for sound absorption model.Secondly, through MATLAB numerical simulation to study sound absorption performance. By this means, the influence of the different parameters such as perforation diameter, thickness, perforation rate, cavity depth on the sound absorption performance are discovered.Thirdly, according to the selected parameters, micro perforated samples are fabricated by laser processing. The theoretical value and experimental value are analyzed. Using impedance tube to measure the sound absorption coefficient value, get the curve of sound frequency and absorption coefficient.Lastly, analyze the experimental data and verify the validity of the test data. Design orthogonal experiment and receive the optimal levels of each parameter, analyze the most significant factors affecting absorption coefficient, select the optimization of structure parameters combination.The results that the sound absorption structures of micro perforated panel affect on the sound absorption coefficient can be getting in the thesis. In order to make the standard of sound-absorbing material model to support the sound absorption coefficient of the sound absorbing body quantity, some beneficial exploration are made by tracing to the source.