Structural Monitoring Using Fiber-Optic Bragg Grating Sensors

For many applications in the aerospace industry, monitoring of structural performance is becoming increasingly important in order to reduce maintenance and inspection costs and enhance efficiency. One of the most attractive sensors to build large area sensor networks has become the fiber-optic Bragg grating. Despite the fact that Bragg grating sensors have been of considerable interest to the structural health monitoring community for the last few years, many challenges associated with applying Bragg grating sensors in real-world applications have not yet been solved. One of the major issues remaining is the method of attaching the sensors to the structure to be monitored. It is essential to understand the optical signal of the sensor and its relation to the actual strain fields in or on the structure. DaimlerChrysler and EADS have studied several solutions for the fiber attachment over the past few years. This paper discusses three of these methods, which are currently under investigation in both lab and field tests.