金属与复材机舱壁板隔声量仿真及声学优化

Sound insulation simulation and acoustic optimization of metal and composite fuselage panels

摘要:

为研究金属及复材对机舱壁板隔声量的影响，建立了隔声量的统计能量模型，并通过均质铝板隔声量的理论计算结果及有限元仿真结果验证其有效性，利用该统计能量模型分析了不同铺层方式对复材板隔声量的影响，对比了等厚度、等面密度条件下金属板和复材板的隔声性能差异，最后通过铺设阻尼优化了复材板的隔声性能。分析结果表明：单向层厚度以及铺层层数的改变对复材板隔声量影响很小；厚度相同时，铝板的隔声量明显高于复材板，而面密度相同时，在高于2 500 Hz的高频段，铝板的隔声量高于复材板，其余频率下二者隔声量相近；阻尼优化后的复材板与优化前相比在2 500 Hz、3 150 Hz和4 000 Hz三个频率处隔声量分别提升1 dB、4.1 dB和18.6 dB，其他频率处隔声量变化较小，证明使用阻尼材料可以有效提高复材板的隔声性能。

Abstract:

In order to study the influence of metal and composite materials on the sound insulation of fuselage panels, a statistical energy model for sound insulation was established, and its effectiveness was verified by the theoretical calculated results of the sound transmission loss of aluminum panels and the simulated results using the finite element simulation method. The statistical energy model is used to analyze the influence of different lay-up configuration of the composite panel on its sound insulation. Then, comparison was made on the sound insulation properties of a metal panel and a composite panel under two conditions: equal thickness, and equal surface density. At last, the damping layers were utilized to enhance the sound insulation properties of the composite panel. The results show that changes in the thickness of the unidirectional composite laminate and the number of the composite laminates have negligible effect on the sound insulation of composite panels. Furthermore, the sound insulation of the aluminum panel is much higher than that of the composite panel with the same thickness. When the surface density is the same, the sound transmission loss of the aluminum panel is higher than that of the composite panel in the frequency range higher than 2 500 Hz, and the sound transmission loss of these two is similar at other frequencies. Although the enhancement at other frequencies are limited, the sound insulation of composite panel with additional damping layers has increased by 1 dB, 4.1 dB and 18.6 dB at frequency of 2 500 Hz, 3 150 Hz and 4 000 Hz, respectively, compared with that without damping layers. This implies the effectiveness of using damping layers as an effective method to enhance the sound insulation of composite materials in civil aviation industry.