局域共振型热-声超材料的概念与设计

The metamaterial has been actively applied to the sophisticated equipment in military strategies of great powers for its superior characteristics which the natural materials do not possess. Because the design of metamaterial is focusing one special function in present stage, such as acoustic insulation or heat shielding merely, it can hardly meet the requirement of multi-physics serving environments. In this project, we break the restriction of single metamaterial and the concept of thermal-acoustic metamaterial (T-AM) is proposed, with the combine of the thermal bandgap and the low-frequency acoustic bandgap which belong to the thermal metamaterial (TM) and locally resonant acoustic metamaterial (LRAM) respectively together. Firstly, we manage to transform the T-AM creation in different sacles to the design of acoustic metamaterial (AM) in TM matrix. To reveal the effecting law and action mechanism of the stress and deformation induced by thermal in the bandgap of AM, the study of performance prediction of LRAM theoretical model is conducted. Then we will explore the existence of acoustic bandgap of the LRAM when it is designed in the TM matrix. In addition, whether the heat flux can be effected when the LRAM cell is in resonant modal also deserves further study. Finally, the sound proof characteristic of the AM with TM matrix and the sound-thermal insulation properties of the T-AM ought to be tested by experiment separately. In conclusion, we intend to realize the design and validation of the novel T-AM in this item, to provide many creative ideas for the sophisticated equipment in heat insulation and sound proof design.

超材料因其天然材料所不具备的超常性能而被各大国积极推进应用于战略尖端装备。当前超材料的设计多为适用于单场如声或热的超材料，不具备既隔声又防热的功能，难适用于多场服役环境的需求。本项目突破单场超材料概念，拟将具有热流带隙的热超材料与低频隔声的局域共振型声超材料合一，创生热-声超材料概念。将无法在同一尺度上设计的热-声超材料难题转化为在热超材料上设计声超材料的问题，开展局域共振型声超材料在热环境下性能预测的理论模型研究，揭示热应力、热变形等对声超材料带隙的影响机制及规律；研究热超材料为基材设计局域共振型单胞产生禁声带隙的可能性、及单胞处于局域共振模态时是否影响热超材料的热流特性；实验测试基于热超材料设计声超材料获得带隙的可能性及热-声超材料的防热、隔声性能。本项目拟初步实现热-声超材料新概念的设计与验证，为尖端装备的防热、隔声设计提供创新性思路。

近年，超材料的出现，为装备结构的防热、降噪、减振设计等工程难题提供了新的解决思路。然而，当前超材料的设计多为适用于单场如声或热的超材料，不具备既隔声又防热的功能，在应用中较难满足装备结构多场服役环境的需求。.本项目以具有低频弹性波带隙的声学超材料和热流弯曲特性的热学超材料为研究对象，揭示了热效应对声学超材料带隙特性的影响规律。并基于此设计提出了一种具有减振与热流弯曲特性的热声双功能超材料，完成了热声超材料从概念的提出、数值研究、结构试件制备、实验测试的完整研究方案，为热声两场超材料的研究提供参考依据。.开展了均匀热环境下声学超材料带隙特性的演变规律研究。从理论分析、数值计算、实验测试分别研究热环境对不同几何构型的声学超材料带隙特性的影响规律。分别从热应力、热变形及两者的耦合效应三个方面开展研究，揭示了不同温度下局域共振结构弹性波带隙的演变规律。.开展了热效应对颗粒声子晶体弹性波带隙的影响特性研究。以一种双原子颗粒声子晶体为研究对象，通过将热效应引入颗粒结构中，理论及数值研究了温度对其弹性波带隙的影响规律。并通过霍普金森压杆装置测试了不同周期颗粒声子晶体受热时，弹性波传播特性。.提出了一种具有热流调控与隔振特性的螺旋复合声子晶体板结构，考察了螺旋复合板的热流调控特性与基体中弧形构件铺设角对其能带结构的调控作用，证实了基于各向异性热超材料设计声超材料获得理想带隙的可能性。.提出了一种具有减振与热流弯曲特性的热声双功能超材料结构，数值、实验研究其热学超材料的热流弯曲特性和声学超材料的带隙特性，并提出完整的结构设计原理。.综上，本项目研究了热环境对弹性波带隙特性的影响规律，设计了一种热声双功能超材料，验证了其弹性波带隙特性以及热流弯曲特性。对尖端装备结构的防热、减振及降噪设计具有重要参考意义。