Airframe Health Monitoring Using Acoustic Emission Crack Detection with Bragg Gratings

Sponsored by: Naval Air Warfare Center, Maryland Industrial Partnerships (MIPS)

Team Member: University of Maryland, College Park

AITHER has developed a breadboard prototype fiber Bragg grating (FBG) based sensing system for detecting acoustic emissions from crack events. The research program was focused on using embedded FBG sensors to monitor or “listen” for crack events of a composite structure. Because of the high frequency nature of these acoustic emission signals, a novel FBG sensor interrogation system was designed and constructed. The Ultra High Speed – Fiber Optic Interrogation System (UHS-FOIS) is a breadboard-design based on passive filtering techniques allowing the data acquisition speed to be limited only by the opto-electronic detection devices. An overview of the research program was presented at SPIE’s conference on Smart Structures and Materials 2003; please see the publications page.

This UHS-FOIS possesses a diverse application potential to long-term monitoring of other structural systems including maritime systems (e.g., ships, oil platforms), spacecraft, large-scale civil infrastructure (e.g., bridges, highways), and other systems where structural integrity, safety, and maintenance schedules must be closely monitored. The acoustic emission crack detection system can be combined with AITHER’s other structural health monitoring sensors and instrumentation to provide a fully integrated solution for monitoring the structural health of aircraft, vessels, and structures. AITHER has developed multiplexing schemes for this sensor system and is currently seeking research investment opportunities to continue development of this cutting edge product line.