Optical Carrier Based Microwave Interferometry for Spatially Continuous Distributed Monitoring of Structural Health

该合同的目标是为结构健康监测（SHM）开发强大的、可嵌入的分布式传感器，以确保国家关键基础设施的持续安全运行。基于光学载波微波干涉测量（OCMI）的新概念，所开发的传感器具有研究正常载荷下结构行为的高测量分辨率，诊断极端载荷下结构完整性的大应变能力，以及大跨度的空间连续性（无暗区），可全面评估结构整体健康状态。将研究OCMI的基础物理，以了解其传感应用的全部能力。将探讨各种工程选择，以制定最佳设计，以最大限度地提高分布式传感能力。基于聚合物光纤（POF）的OCMI传感器将被设计、开发和表征，用于大应变和裂纹检测的分布式测量，以证明新的OCMI概念在SHM中的有效性。如果成功，这项研究的结果将导致使SHM技术能够确保国家日益恶化的基础设施的安全运行，并在灾害响应和紧急疏散期间促进关键任务服务。该研究将建立一个深刻的理解，设计集成的微波光学系统，以满足各种传感需求。分布式裂纹检测和量化将使用灵活且鲁棒的基于POF的OCMI传感器来实现，该传感器具有增强的可部署性、可嵌入性、可靠性和大应变能力。本研究中开发的基本知识和方法也可转移到SHM的其他关键应用中，例如力、载荷、疲劳和腐蚀的分布式监测。

The objective of this award is to develop robust, embeddable, distributed sensors for structural health monitoring (SHM) to ensure continuing safe operations of the nation's critical infrastructures. Based on the novel concept of optical carrier based microwave interferometry (OCMI), the developed sensors have the long-desired high measurement resolution for studying structural behaviors under normal loads, the large strain capability for diagnosing the structural integrity under extreme loads, and the spatial continuity (no dark zones) over a large span for comprehensive evaluation of the health status of the structure as a whole. The fundamental physics of OCMI will be studied to understand its full capabilities for sensing applications. The various engineering options will be explored to formulate an optimal design for maximized distributed sensing capability. Polymer optical fiber (POF) based OCMI sensors will be designed, developed and characterized for distributed measurement of large strain and crack detection to demonstrate the effectiveness of the new OCMI concept for SHM.If successful, the results of this research will lead to an enabling SHM technology to ensure the safe operation of the nation's deteriorating infrastructures, and facilitate mission-critical services during disaster responses and emergency evacuations. The research will establish an insight understanding to design integrated microwave-optics systems for various sensing needs. Distributed crack detection and quantification will be implemented using flexible and robust POF based OCMI sensors with enhanced deployability, embeddability, reliability and large strain capability. The fundamental knowledge and methodologies developed in this research are also transferrable to other critical applications in SHM such as distributed monitoring of force, load, fatigue and corrosion.