Wave Control via Phononic Crystals with Adaptively Relaxed Cell Symmetry

通过具有自适应松弛单元对称性的声子晶体进行波控制

• 批准号: 1266089
• 负责人: Stefano Gonella
• 金额: $ 28.94万
• 依托单位: University of Minnesota-Twin Cities
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2013
• 资助国家: 美国
• 起止时间: 2013-06-01 至 2017-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1266089&HistoricalAwards=false
• 关键词: Wave; Control; via; Phononic; Crystals

The objective of this award is to introduce a family of crystal-like metamaterials with adaptively relaxed cell symmetry (ARCS) and demonstrate their applicability as tunable acoustic manipulators. The virtue of ARCS crystals lies in their ability to operate in relatively low-frequency regimes, where the performance of wave management methodologies relying exclusively on phononic bandgaps is compromised. The investigation of the ARCS concept will be conducted using a prototype honeycomb with a periodic population of beam resonators instrumented with patches of piezoelectric material. The cell symmetry is relaxed through the modulation of the local effective stiffness of a selected cluster of resonators, which results in the establishment of a non uniform distribution of effective mechanical properties in the medium. The property tuning is enforced through the activation of appropriate sequences of piezoelectric elements of the activation cluster, according to the desired degree of symmetry relaxation. The investigation will be verified by a set of experiments performed using a 3D scanning laser vibrometer. If successful, this research will provide a strategy to achieve versatile acoustic control devices that are immune to some major drawbacks that affect metamaterials based approaches, such as passivity and drastic frequency limitations. The technological applications that would greatly benefit from the ARCS concept include isolation systems, mechanical filters and directional actuators and sensors. The methodology for laser-enabled wave reconstruction that will be specifically developed for this work will provide new general protocols for the experimental characterization of synthetic structural materials at large. This work will open new avenues for research in energy harvesting, towards the design of fully autonomous wave control devices. It will also provide a platform and implement a plan to realize partnerships with local middle and high schools for thematic projects aimed at promoting science and engineering among children and teenagers.

该奖项的目的是介绍一类具有自适应松弛晶胞对称性(ARCs)的晶体状超材料，并展示它们作为可调谐声学操纵器的适用性。ARC晶体的优点在于它们能够在相对较低的频率下工作，在这种情况下，完全依赖声子带隙的波管理方法的性能会受到影响。对弧形概念的研究将使用带有周期性波束谐振器的蜂窝原型进行，这些波束谐振器由片状的压电材料组成。通过调制选定的谐振器簇的局部有效刚度来松弛晶胞对称性，这导致在介质中建立有效力学性能的非均匀分布。根据所需的对称性松弛程度，通过激活激活簇的适当的压电元件序列来实施属性调节。这项调查将通过使用3D扫描激光测振仪进行的一系列实验来验证。如果成功，这项研究将提供一种策略，以实现多功能声学控制设备，这些设备不会受到影响基于超材料的方法的一些主要缺陷的影响，例如无源和严重的频率限制。ARC概念将极大地受益于技术应用，包括隔离系统、机械过滤器以及定向执行器和传感器。为这项工作专门开发的激光使能波重建方法将为合成结构材料的实验表征提供新的通用方案。这项工作将为能量收集的研究开辟新的途径，朝着全自动波控设备的设计迈进。它还将提供一个平台，并实施一项计划，以实现与当地初中和高中的合作伙伴关系，开展旨在促进儿童和青少年科学和工程的主题项目。