High-Velocity Impact Detection and Localization Enabled by 10 MSa/s Sample- Rate FBG Interrogation

Abstract

Real-time structural health monitoring (SHM) systems for airborne structures can help detect and predict damage to critical components. This study demonstrates a system for real-time detection and evaluation of high-velocity foreign object impacts on composite structures using fiber Bragg gratings (FBGs). A set of fiber Bragg gratings were applied to a composite helicopter blade, and by using high-speed and wide frequency-band FBG interrogation, we demonstrate object impact detection made by projectiles of various materials and weights, with speeds from 100 m/s up to 200 m/s and their respective elastic wave propagation along the blade. Early impact damage detection has the potential to reduce the chance of critical failure and decrease aircraft downtime caused by rigorous and time-consuming non-destructive inspections.