薄板声波超材料各向异性质量调控的理论与实验研究

Thin-plate acoustic metamaterials whose macroscopic mechanical behaviors can be tailored by artificially designed microstructures have been paied much attention recently, and have been utilized to realize many advanced functional sonic materials. However, current design strategy for thin-plate metamaterials doesn't realize effective mass with arbitrary anisotropy, which may constrain their engineering applications. The purpose of the project is to design metamaterials with arbitrarily anisotropic effective mass based on thin-plate periodic join-structures, and construct the design theory of thin-plate metamaterials for their application to acoustic wave control. To this end, based on the analyses on the coupling interactions between flexural vibrations of thin plates and ambient fluid materials, the project establishes the dynamic homogenization model of thin-plate metamaterials based on the dispersion equivalence and retrieval method of effective parameters, and derive the correlation between effective mass and microstructure parameters. Acoustic field measurement systems will be constructed, and thin-plate metamaterials are fabricated and experimentally tested. Based on above analyses, the design theory for thin-plate metamaterials with arbitrarily anisotropic effective mass is established and serving for their applications to acoustic wave control.

薄板声波超材料由于其良好的可设计性正受到广泛关注，并已初步用于一些先进声功能材料的设计，但目前提出的薄板构型很难实现任意的各向异性质量，限制了其在声传播调控方面的应用。项目将以周期搭接薄板结构实现任意各向异性质量为研究目标，建立该类超材料等效质量与微观结构的关联，在此基础上给出具有任意各向异性质量薄板声波超材料的设计方法。为此，项目在系统研究具有谐振单元薄板结构与环境液体相互作用规律基础上，基于频散关系等效和等效参数反演等方法建立周期搭接薄板结构动态均匀化理论，给出微结构参数与宏观各向异性质量的关联关系；并搭建声场测试系统，对薄板超材料进行实验制备和声传播特性测试。综合以上研究成果，给出薄板超材料实现任意各向异性质量的设计理论，为下一步在声传播调控方面的应用奠定研究基础。

薄板声波超材料具有良好的可设计性，并已初步用于先进声功能材料的设计，但传统薄板构型很难实现任意各向异性质量，限制了其在声传播调控方面的深入应用。项目以薄板超材料实现各向异性质量用于声波调控为研究目标，深入开展了薄板超材料的动态均质化原理，设计和制备方法及相关应用探索研究。取得的主要研究成果有：（1）提出了薄板声波超材料的动态均质化方法，揭示了微结构参数对宏观各向异性质量的影响机制，形成了薄板超材料用于声传播调控的微结构设计原理；（2）研制出具备声压幅值和相位同步采集功能的二维声场扫描测试系统，开展了薄板超材料的制备及其声特性刻画的实验研究；（3）设计出用于封闭空腔结构声辐射抑制、声波绕射隐身和低频超吸声的薄板超材料功能结构，并通过了数值模拟验证。基于上述研究进展，发表SCI收录期刊论文2篇，包括知名声学期刊Journal of the Acoustical Society of America，知名物理期刊AIP Advances。研究成果在隔声降噪、声隐身等领域具有重要的应用价值。