复合材料机身结构声学特性及影响参数分析

针对复合材料(以下简称"复材")结构进行声振分析,通过无限大障板理论和波动方程,分析复材平板和曲板结构的传声损失,并利用统计能量法分析壁板的隔声性能,与文献中的实验结果进行对比,验证建模的有效性。然后将复合材料机身结构等效成一个复材圆柱壳体结构,分析不同参数,包括压差、曲率半径、长度、铺层角度、纤维材料、加筋等对结构隔声性能的影响。最后与金属机身结构进行隔声性能对比,发现:在环频率与吻合效应频率之间,金属机身结构的传声损失明显大于复材机身结构,而在吻合效应频率以上频段,由于复材结构的吻合效应频率向低频移动,其传声损失好于金属机身结构。

Acoustic characteristics and effective factor analysis of the composite fuselage

The infinite panel theory and the wave equation have been applied to analyze the transmission loss of the composite material structures, including the flat and curve structures. The statistic energy analysis (SEA) is used to model a composite panel, and the simulated results are validated by test data. Then the composite fuselage would be equivalent to a cylinder shell modeled by SEA, and the effects of the pressurized difference, curve radius, shell length, layer angle, fiber material, and reinforcement have been analyzed to this composite fuselage. Lastly, the sound insulation performance of the composite fuselage has been compared to that of the metal fuselage. The results show that the transmission loss of the latter is better than the former between the range of the ring frequency and coincidence frequency, but it will show an opposite phenomenon above the coincidence frequency, because the coincidence frequency of the former has a shift to the low frequency compared to the latter.