Fully Integrated Hybrid “Piezoelectric/Fiber Optic” Acousto-Ultrasound Sensor Network (FAULSense™) SHM System

Acoustic-ultrasound (AU) sensing is an effective, and powerful tool for the non-destructive testing and evaluation of composite and metallic material structures. The AU technology consists of sending and receiving low frequency acoustic pulses at a predetermined angle of incidence into a material under inspection. Analysis of the detected acoustic-ultrasound waveform characteristics provides a clear representation of the mechanical state of the structure.

Our research group at Redondo Optics is currently in the process of testing and demonstrating the performance demonstration of a unique fully integrated, miniature, lightweight, and power efficient, hybrid “piezoelectric/fiber optic” acousto-ultrasound sensor network (FAULSense™) SHM system suitable for the real-time, in-situ, and un-attended detection, identification, localization, classification, of static and dynamic load environments representative of the structural state of large rotorcraft structures. The hybrid PZT/FBG FAULSense™ SHM system is a highly integrated, ultra-sensitive, high frequency response (DC to 5-MHz), acousto-ultrasound structural health monitoring (SHM) system that uses a wide area coverage flexible and conformal strip-patch sensor network integrating a stack of thin-film piezoelectric actuators used to input control structural excitation of acoustic signals over the entire, or discrete locations, of an aircraft structure (fuselage, wings, tails, rotor blades, etc.), and a distributed array of fiber Bragg gratings (FBG) acousto-ultrasound sensors used to detect and measure the corresponding waveform structural response to the PZT excitation signals, that contains structural information representative of potential damage associated with excessive loads, fatigue, impacts, fractures, delamination, corrosion, radiation, and structural damage of large composite and metallic structures commonly found in military rotorcraft.