Structural health monitoring on an unmanned aerial vehicle wing's beam based on fiber Bragg gratings and pattern recognition techniques

Composite materials have been extensively used on new aircraft airframes because of their advantages over metallic materials. This represents a difficulty for damage detection, a vital task for safety on the aerospace industry, as most nondestructive testing techniques are not effective on these materials since those usually present internal failures like delaminations which are difficult to detect. A miniaturized strain acquisition and wireless transmission system is presented alongside with a novel technique for structural behavior assessment, based on the use of Fiber Bragg Gratings to measure strains and non-supervised classification techniques to recognize different operational conditions. Operational tests were performed on an Unmanned Aerial Vehicles wing's beam, made of composite materials with the sensors embedded during its manufacturing. Strain measurements were processed using an Optimal Baseline Selection methodology. The tests performed proved the system's capability to identify and separate different operational conditions for a healthy structure, based on the analysis of its strain fields. The implementation of this methodologies can lead to perform real-time damage detection on aerospace complex structures made of composite materials. (C) 2017 The Authors. Published by Elsevier B.V.