DC-XA structural health monitoring fiber-optic based strain measurement system

Methods for reducing weight, size, and complexity of flight systems are especially desirable in aerospace vehicles. To answer the challenge the Delta Clipper eXperimental Advanced (DC-XA) program has developed numerous new technologies including a Bragg-rating based fiberoptic system used for measuring strain on the vehicle's liquid hydrogen fuel tank. This is one of the first known aerospace applications of a practical fiberoptic strain measurement system. The system utilizes four parallel channels of serially multiplexed fiberoptic sensors. Its basic advantages include reduced signal cable complexity and weight, wide temperature operation, efficient use of wavelength bandwidth and power, and potentially small signal conditioner size. This paper presents the design and development of the system as well as performance data and experimental results. The presentation will also discuss advantages over conventional sensor systems, the system's capabilities and drawbacks, and next generation improvements.