Study on Sound Insulation Performance of Broadband Membrane-type Acoustic Metamaterials
Aiming at the optimization of the sound insulation performance of automobile front coaming in middle and low frequency band,a membrane-type acoustic metamaterial structure with X-shaped swing arm as the central mass block is proposed.The sound-structure coupling module in COMSOL simulation software is used to analyze the overall sound trans-fer loss(STL)curve,the mean normal displacement of the film surface,the equivalent parameters,the coupled vibration modes and the control law of the factors affecting the sound insulation.The results show that the membrane-type acoustic metamaterial structure with the X-shaped central mass block has excellent sound insulation frequency band bandwidth and sound insulation amplitude,the bandwidth is close to 1 332 Hz and the peak value of sound insulation is 54 dB;In the new structure,the X-shaped swing arm can merge the discontinuous sound insulation peaks generated by the surrounding mass blocks,thus widening the sound insulation band and improving the overall sound insulation performance of the structure.The increase of film thickness and preload will make the STL curve shift towards the high frequency side as a whole,while the increase of the elastic modulus of the X-shaped swing arm will only make the second valley of the STL curve move to-wards the high frequency slightly.The composite structure composed of steel plate can effectively improve the average sound insulation of front coaming plate.This study has expanded the engineering application prospect of membrane-type acoustic metamaterial structures in the field of noise control in low and medium frequency bands.
万方数据
维普
