Collaborative Research: Conformal Gradient-Index Lenses for Ultrasonic Wave Amplification and Improved Diagnostics

合作研究：用于超声波放大和改进诊断的共形梯度折射率透镜

• 批准号: 1914583
• 负责人: Serife Tol
• 金额: $ 36.85万
• 依托单位: Regents of the University of Michigan - Ann Arbor
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-06-15 至 2023-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1914583&HistoricalAwards=false
• 关键词: Collaborative; Research; Conformal; Gradient; Index

Current structural systems are made of homogenous materials such as cast iron, wrought iron, bare steel, and brittle plastic, which are highly susceptible to failure and therefore require accelerated inspection and repair. Ultrasonics is a nondestructive evaluation method based on propagating elastic waves in structures, which are affected by defects in the structure and can therefore be used for damage diagnostics. However, in conventional structures, the amplitude of elastic waves decays with distance due to spreading/scattering, which limits the detectability of critical defects. In this research, new structural systems will be designed with an embedded or externally added lens so that ultrasonic signals can be focused and amplified as they propagate in the structure. In this way, ultrasonic wave energy can be transmitted and preserved over long distances. The research will allow detecting defects at their earliest stage and preventing unexpected failures. The target application will be pipeline systems due to their high susceptibility to failure. Therefore, results from this research will benefit the U.S. economy and society. This multi-disciplinary research encompasses metamaterials, sensors, additive manufacturing, structural monitoring, and design. The project features a synergistic educational component that integrates the strengths of two institutions in recruiting students who are underrepresented in engineering. In particular, female undergraduate and graduate students at both institutions will be connected via mutual workshops and the Society of Women Engineers (SWE).This research will introduce a conformal gradient-index (GRIN) metamaterial lens as part of a structural system such that elastic waves will be amplified as they propagate through the non-planar structure. With the GRIN lens, different ultrasonic wave modes (i.e., longitudinal, flexural, or torsional) will be focused and transmitted such that higher frequencies (50-200 kHz) will be able to propagate with the increased sensitivity to structural damage. The GRIN lens will be designed by varying the refractive index of unit cells, and the existing model of the GRIN lens for flat surfaces will be modified for conformal surfaces. The metamaterial lens layer will be created with 3D printing, which will allow more practical and light weight structures to be easily integrated into the host structure. Additionally, a novel composite pipe structure, produced with multi-material additive manufacturing technologies, will be designed with the embedded metamaterial lens to address the highest risk of major incidents from the conventional materials used in pipelines.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

目前的结构系统由同质材料制成，如铸铁、锻铁、裸钢和脆性塑料，这些材料极易发生故障，因此需要加速检查和维修。超声波是一种基于在结构中传播弹性波的无损评估方法，其受到结构中缺陷的影响，因此可用于损伤诊断。然而，在常规结构中，由于扩展/散射，弹性波的振幅随距离衰减，这限制了临界缺陷的可检测性。在这项研究中，新的结构系统将设计一个嵌入式或外部添加的透镜，使超声波信号可以集中和放大，因为他们在结构中传播。通过这种方式，超声波能量可以长距离传输和保存。该研究将允许在最早阶段检测缺陷并防止意外故障。目标应用将是管道系统，因为它们对故障的敏感性很高。因此，这项研究的成果将有利于美国的经济和社会。这种多学科研究包括超材料，传感器，增材制造，结构监测和设计。该项目的特点是一个协同的教育组成部分，整合了两个机构在招收工程专业代表性不足的学生方面的优势。特别是，两所大学的女本科生和女研究生将通过相互的工作坊和女工程师协会（SWE）相互联系。本研究将引入共形梯度折射率（GRIN）超材料透镜作为结构系统的一部分，使弹性波在非平面结构中传播时被放大。利用GRIN透镜，不同的超声波模式（即，纵向、弯曲或扭转）将被聚焦和传输，使得更高的频率（50-200 kHz）将能够以增加的对结构损伤的敏感性传播。GRIN透镜将通过改变单位晶胞的折射率来设计，并且用于平坦表面的GRIN透镜的现有模型将针对共形表面进行修改。超材料透镜层将通过3D打印创建，这将使更实用且重量更轻的结构能够轻松集成到主体结构中。此外，采用多材料增材制造技术生产的新型复合管道结构将采用嵌入式超材料透镜进行设计，以解决管道中使用的传统材料导致的重大事故的最高风险。该奖项反映了NSF的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

项目成果

Torsional wave focusing in cylindrical structures with the conformal gradient-index phononic crystal lens

• DOI: 10.1063/5.0050295
• 发表时间: 2021-05
• 期刊: Journal of Applied Physics
• 影响因子: 3.2
• 作者: G. Okudan;H. Danawe;D. Ozevin;S. Tol

Conformal gradient-index phononic crystal lens for ultrasonic wave focusing in pipe-like structures

• DOI: 10.1063/5.0012316
• 发表时间: 2020-07-13
• 期刊: APPLIED PHYSICS LETTERS
• 影响因子: 4
• 作者: Danawe, Hrishikesh;Okudan, Gorkem;Tol, Serife
• 通讯作者: Tol, Serife

Finite-Frequency Topological Maxwell Modes in Mechanical Self-Dual Kagome Lattices

• DOI: 10.1103/physrevlett.129.204302
• 发表时间: 2022-11-10
• 期刊: PHYSICAL REVIEW LETTERS
• 影响因子: 8.6
• 作者: Danawe, Hrishikesh;Li, Heqiu;Tol, Serife
• 通讯作者: Tol, Serife

Controlling the thickness dependence of torsional wave mode in pipe-like structures with the gradient-index phononic crystal lens

用梯度折射率声子晶体透镜控制管状结构中扭转波模式的厚度依赖性

• DOI: 10.1016/j.ultras.2022.106728
• 发表时间: 2022
• 期刊: Ultrasonics
• 影响因子: 4.2
• 作者: Okudan, Gorkem;Xu, Chenxi;Danawe, Hrishikesh;Tol, Serife;Ozevin, Didem
• 通讯作者: Ozevin, Didem

Harnessing negative refraction and evanescent waves toward super-resolution Lamb wave imaging

• DOI: 10.1063/5.0152717
• 发表时间: 2023-07
• 期刊: Applied Physics Letters
• 影响因子: 4
• 作者: H. Danawe;S. Tol