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噪声水平是现代飞机封闭腔室设计的重要指标,设计中单纯地对壁板进行加肋处理虽能显著降低噪声但会大大增加结构质量,为此对由封闭腔室构成的结构-声耦合系统进行了减重降噪优化研究。基于结构-声耦合有限元模型,利用有限元软件ACTRAN计算了频谱加载时舱内的声压响应。通过试验对简化处理及数值计算进行了验证,并修正了相关模型参数。为了降低结构质量,以加强肋为边界对舱门壁板进行了分区,通过对各个区域壁板厚度及肋条截面积的优化设计,使系统动刚度分配更趋合理,降低了声辐射能量以及结构-声腔的耦合性,从而实现了在满足噪声约束条件下减轻结构质量的目标。本文的工作对实际工程中由加肋壁板所构成的类似结构的减重降噪设计有着较好的工程指导价值。
The noise level is an important indicator of the design of a modern aircraft closed chamber. Simply adding ribs to the siding in the design can significantly reduce the noise but greatly increase the quality of the structure. Therefore, the structural-acoustic coupling system Carried out weight loss and noise reduction optimization. Based on the structure-acoustical coupling finite element model, the acoustic pressure response in the cabin with the spectrum loading was calculated by finite element software ACTRAN. The simplification and numerical calculation are verified through experiments, and the relevant model parameters are corrected. In order to reduce the quality of the structure, the baying panels are partitioned by the stiffener ribs. By optimizing the wall thickness and the rib cross-sectional area in each area, the dynamic stiffness distribution of the system is more reasonable and the sound radiation energy and structure - acoustic coupling, thus achieving the goal of reducing the structural mass while meeting the noise constraints. The work in this paper has a good engineering guiding value for the weight reduction and noise reduction design of the similar structure composed of ribbed siding in practical engineering.