Fiber Optic Acoustic Emission System for Structural Health Monitoring of Composite Pressure Vessels

Pressurized systems and pressure vessels used in NASA ground-based and flight-based applications including fuel tanks, composite overwrapped pressure vessels (COPVs), and composite tankage commonly suffer from several types of degradation including fatigue, cracking, lack of bonding, and leakage. Veraphotonics proposes to develop a pressure vessel leak and damage detection system. In a large vessel, in-line inspection using health-monitoring sensors would provide structural integrity assessment, reduce maintenance, and eliminate potential points of failure. Acoustic Emission (AE) method is the most prevalent method that provides continuous monitoring for leak and damage detection as well as estimates the location of leak or damage in pressure vessels. In this SBIR Phase I project, the feasibility of a novel laser-based interrogation technique AE method for the detection of leak and damages in liquid-filled vessel instrumented with FBG sensors will be performed in laboratory and field vessels including COPVs. Based on laboratory and field test measurements, we will optimize the FBG sensors and the system to reduce or eliminate the acoustic background noise from the vessel environment. In Phase II all the FBG sensors will be integrated on a single optical fiber and interrogated using a compact, battery powered interrogation device with wireless data transmission capability.