Optical Fiber-Based Corrosion Sensors for Aging Aircraft

摘要

Optical fiber corrosion sensors are being developed to address the high service costs associated with current structural maintenance procedures of civilian and military assets. A distribution optical fiber sensor system will help reduce the costs associated with corrosion damage and extend the lifetime of existing assets. Annual national losses in time, labor, materials, and systems have been estimated in the billions of dollars. Additional costs arise from system downtime that results from disassembly procedures to locate corrosion damage in remote locations. Furthermore, the potential to damage other system parts during maintenance is increased when disassembly and reassembly occur. The development of on-line optical fiber sensors capable of detecting corrosion would eliminate a significant portion of the maintenance costs. We present recent test results using optical fiber long-period grating (LPG) corrosion sensors. With the appropriate coating, the sensors can be designed to detect water, pH or metal-ions in otherwise inaccessible regions of the aircraft. The LPG sensors can be rendered immune to temperature cross- sensitivity, multiplexed along a single fiber, and can be demodulated using a simple, low-cost spectrum analyzer.