Multifunctional Mechanoluminescent Composites for Autonomous Impact Detection of Aerospace Structures

Abstract

In this study, an impact sensor module was devised and integrated in honeycombcored composites to develop multifunctional structural composites capable of autonomously detecting impact occurrences on aerospace structures. The sensor module was devised through integration of a fracto-mechanoluminescent (FML) material, optical fibers, and photodiode. The multifunctional structural composites were fabricated by embedding the sensor module in honeycomb-cored composites. Under impact occurrences, FML material in the sensor module emits light (i.e., sensor signal) to be transferred through the optical fiber and detected by a photodiode. Impact sensing capability was validated by subjecting the multifunctional composites to impact loading using a drop hammer tester with various impact energy. Analysis of test data was performed by factorial design of experiments to acquire regression model for understanding relationship between impact energy and sensor output, which can be used for designing FML materials, sensor modules, and multifunctional composites.