Synthetic Phase Tuning of Acoustic Guided Waves

声导波的合成相位调谐

• 批准号: 0218648
• 负责人: Shi-Chang Wooh
• 金额: --
• 依托单位: Massachusetts Institute of Technology
• 依托单位国家: 美国
• 项目类别: Continuing grant
• 财政年份: 2003
• 资助国家: 美国
• 起止时间: 2003-01-01 至 2004-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0218648&HistoricalAwards=false
• 关键词: Synthetic; Phase; Tuning; Acoustic; Guided

ABSTRACTThe objective of this research program is to study and develop an improved guided wave phase tuning technique and its practical applications to nondestructive evaluation (NOE) for inspecting thin and slender members in civil, mechanical and aerospace structures. An extended study of a novel method referred to as "synthetic phase tuning" (SPT) is being developed through this project, which could resolve many critical problems associated with guided waves by eliminating the complexities due to their multimodal and dispersive nature. The innovative concept of the SPT is to reinforce a specific wave mode of interest while suppressing or squelching undesired wave modes by constructing a phase-tuned wave in a virtual domain. This operational scheme may allow for extremely flexible guided wave pulse-echo operations with excellent spatial and temporal resolutions.The program is to understand the phase-tuning mechanisms and to study the wave-material (structure) interactions using various analytical and numerical methods. Various influencing factors such as the characteristics of spatio-temporalloading and transducer parameters, e.g., element width, number of elements, inter-element spacing, operating frequency, are investigated both theoretically and experimentally. In addition, the SPT scheme is extended using the laser- ultrasound techniques in order to relax the current limitations of narrow signal bandwidth.The concept of SPT may have a substantial and direct impact not only on scientific and technological advancements in the field of NOE, condition assessment, and health monitoring,but also on the industrial sectors in NOE manufacturing and services. Although the focus is specifically on NOE, the method does not preclude extensions to a broad spectrum of disciplinary fields such as communication, geophysical explorations, structural control, and MEMS.

摘要本课题旨在研究和开发一种改进的导波相位调谐技术及其在民用、机械和航天结构中细长构件无损检测中的实际应用。该项目正在对一种被称为“合成相位调谐”（SPT）的新方法进行扩展研究，该方法可以通过消除导波多模态和色散特性带来的复杂性来解决与导波相关的许多关键问题。SPT的创新概念是通过在虚拟域中构造相位调谐波来增强感兴趣的特定波模式，同时抑制或压制不需要的波模式。这种操作方案可能允许极其灵活的导波脉冲回波操作，具有良好的空间和时间分辨率。该计划旨在了解相位调谐机制，并使用各种分析和数值方法研究波与材料（结构）的相互作用。对元件宽度、元件个数、元件间距、工作频率等时空加载特性和换能器参数的影响因素进行了理论和实验研究。此外，利用激光-超声技术对SPT方案进行了扩展，以放宽目前信号带宽狭窄的限制。SPT的概念不仅可以对NOE、状态评估和健康监测领域的科学和技术进步产生重大和直接的影响，而且还可以对NOE制造和服务中的工业部门产生重大和直接的影响。虽然重点是NOE，但该方法并不排除扩展到广泛的学科领域，如通信，地球物理勘探，结构控制和MEMS。