Structural Health Monitoring Using Fiber Optic Sensing

A system for structural health monitoring of ships using fiber optic sensors will be developed. The baseline system to be investigated is a proprietary spread spectrum interrogation system under development by Lucent Technologies, which will support monitoring of strain, temperature, and potentially other parameters, continuously in space and time. Ideally, this system will be able to interrogate the intrinsic sensitivities of fiber to strain to measure mechanical strain and temperature. If greater sensitivity is required, Bragg grating reflectors will be integrated into the system. A test rig will be built to simulate hull and decking areas which are to be monitored by the system, and the potential performance of bare fibers, fibers with intrinsic Bragg grating sensors, and telemetry systems based on proprietary Lucent technology and variations on that technology, including wavelength multiplexing, will be tested with static and slowly varying structural strains. A system capable of meeting Navy requirements and which can be interfaced with other automated systems will be defined and a plan to demonstrate this system in Phase II will be developed.