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.