微穿孔板-三聚氰胺吸音海绵-空腔复合结构声学性能优化设计

基于Johnson-Champoux-Allard（JCA）模型和微穿孔板理论，利用传递矩阵法建立了三聚氰胺吸音海绵不同填充方式形成的复合结构的吸声系数理论模型，并比较了其吸声性能：与单层微穿孔板结构a相比，微穿孔板-吸音海绵复合结构b和微穿孔板-吸音海绵-空腔复合结构c的吸声性能均有较大提升，微穿孔板-空腔-吸音海绵复合结构d的提升效果次之。分析了几何参数对复合结构b的吸声性能的影响，得出：微穿孔板的孔径越小，复合结构在中高频段的吸声效果越好；厚度越大，复合结构在高频段的吸声性能越低；穿孔率越大，复合结构在低频段的吸声性能越低；吸音海绵厚度的增加在总体上有利于提高复合结构的吸声效果。基于粒子群算法对复合结构b和c的吸声性能进行了优化，结果表明：与优化前的复合结构b相比，优化后的复合结构c的平均吸声系数从0.565 4提升至0.751 9；与优化后的复合结构b相比，其吸声性能几乎不变，但吸声材料厚度减少了30%，在保持良好吸声性能的同时实现了轻量化。

Optimization of the acoustic performance of micro-perforated panel-melamine sound-absorbing sponge-cavity composite structures

Based on the Johnson-Champoux-Allard (JCA) model and micro-perforated panel theory, theoretical models of the sound absorption coefficient of the composite structures formed using different filling methods of melamine sound-absorbing sponge have been established by a transfer matrix method, and the sound absorption performances of the resulting materials were compared. The results show that compared with the single-layer micro-perforated panel structure a, the sound absorption performances of the micro-perforated panel-sound-absorption sponge composite structure b and the micro-perforated panel-sound-absorption sponge-cavity composite structure c are greatly improved, whilst the improvement afforded by the micro-perforated panel-cavity-sound-absorption sponge composite structure d is less marked. The influence of geometric parameters on the sound absorption performance of the composite structure b was analyzed. The results show that the smaller the aperture of the micro-perforated panel, the better the sound absorption effect of the composite structure in the middle and high frequency bands. However, increasing the thickness of the composite structure reduced the sound absorption performance in the high frequency band and increasing the perforation rate reduced the sound absorption performance in the low frequency band. An increase in the thickness of sound-absorbing sponge is generally beneficial in terms of improving the sound absorption effect of the composite structure. The sound absorption performances of composite structures b and c were optimized based on particle swarm optimization. The results show that compared with the composite structure b before optimization, the average sound absorption coefficient of the optimized composite structure c increases from 0.565 4 to 0.751 9. Compared with the optimized composite structure b, the sound absorption performance of the optimized composite structure c is almost unchanged, but the thickness of the sound absorption material is reduced by 30%, which offers the advantage of light weight while maintaining good sound absorption performance.