摘要
针对声学覆盖层低频吸声问题,建立将局域共振结构内嵌到空腔覆盖层的复合结构,通过分析模态振型和振动位移云图得出其吸声机理,以复合结构的几何参数和材料参数为控制变量,以10~1000 Hz频段内的吸声系数最大为优化目标,以Nelder-mead单纯形法为优化方法,对建立的模型进行优化设计。研究结果表明:1)复合结构的吸声机理为下半部分空腔变形实现纵波向横波的转化,局域共振结构的向上振动消耗声能,二者共同作用,提高吸声系数;2)复合结构经几何参数优化和材料参数优化后,吸声系数分别提高了13%和26%;3)吸声性能提高的原因为优化后,局域共振结构在更低频处出现反共振振型,结构动能密度较优化前提高了一个数量级,因此吸声性能提高。研究结果可为声学覆盖层的设计提供理论基础。
In order to solve the low frequency sound absorption problem of acoustic cover,a composite structure with local resonance structure embedded into the cavity cover was established.Its sound absorption mechanism was obtained by analyzing the modal shape and the vibration displacement nephogram.The geometric parameters and material parameters of the composite structure were taken as the control variables,and the maximum sound absorption coefficient in the 10~1000 Hz frequency band was optimized.The Nelder-mead simplex method is used to optimize the model.The results show that:the sound absorption mechanism of the composite structure is as follows:the deformation of the lower part of the cavity can transform the p-wave into s-wave,and the upward vibration of the local resonance structure consumes the sound energy.The sound absorption coefficient is increased by the joint action of the two.The sound absorption coefficient of the composite structure is increased by 13%and 26%after the optimization of geometric parameters and material parameters,respectively.The reason for the improvement of sound absorption performance is that after optimization,anti-resonance mode appears at lower frequency of the local resonance structure,and the kinetic energy density of the structure is increased by one order of magnitude compared with that before optimization,so the sound absorption performance is improved.The results can provide a theoretical basis for the design of acoustic cladding.
作者
王佳蓓
周浩
张健
WANG Jia-bei;ZHOU Hao;ZHANG Jian(Naval University of Engineering,Wuhan 430033,China;No.91604 Unit of PLA,Yantai 265700,China)
出处
《舰船科学技术》
北大核心
2022年第22期43-49,共7页
Ship Science and Technology
基金
国家自然科学基金资助项目(11602300)。
