Optical fibers applied to aerospace systems prognostics: design and development of new FBG-based vibration sensors

Abstract

Abstract Future generation actuation systems will be characterized by ever-increasing complexity. In this context, it will be necessary to adopt advanced health monitoring strategies to guarantee a high level of operational safety and system reliability. Prognostics and Health Management (PHM) is thus emerging as an enabling discipline for the design and operation of future advanced, complex systems. Smart systems with embedded self-monitoring capabilities are nowadays required in order to provide early faults identification and to perform innovative diagnostic and prognostic functions. In aerospace applications, the use of smart sensors could replace various types of traditional sensing elements, commonly used in structural monitoring with the additional capability of performing some prognostics or diagnostics tasks. This work proposes the first results of an experimental campaign aimed at evaluating and validating various packaging solutions for vibration amplification and detection using optical sensors (Fiber Bragg Gratings, FBGs), since characteristics frequencies can be good prognostics indicators of particular failure modes of a system. Several test samples were created by using 3D printed PLA and compared using a variety of bench tests. Results were compared in order to identify the strengths and weaknesses of the various proposed configurations, and were validated by comparing them with numerical simulations and experimental measurements performed with traditional sensors such as strain gages and accelerometers.