Description: Intelligent Fiber Optic Systems and Auburn University propose a Fiber Bragg Grating (FBG) integrated Structural Health Monitoring (SHM) sensor system capable of providing in-situ crack detection, location and quantification of damage, as well as validating structural models, using recent advances in non-contact, non-destructive dynamic testing of composite structures. The key innovation is an FBG-based SHM system for detecting, locating and quantifying crack and de-lamination in composite structures such as smart, composite jet engine vanes with embedded FBG sensor systems. These new techniques make it possible to analyze complex structures not only non-destructively, but also without physically contacting or implanting electrical elements into test samples. The state-of-art FBG sensor system will be capable of measuring strains, stress, temperature and pressure and monitor damage to the structure under test at the same time at wide temperature ranges. IFOS and its university research collaborator will investigate the feasibility of such multi-functional FBG sensors with great potential for SHM. Advanced signal processing, system identification and damage identification, location and quantification algorithms will be applied. Potentially, the solution could evolve into an autonomous onboard monitoring system to inspect and perform Non-Destructive Evaluation and SHM.

Benefits: For aerospace vehicle health monitoring applications, this fiber sensor network and method will significantly increase the sensing capability, extending the applicability of grating-based fiber-optic sensors systems and at low cost, as well as enabling a dynamically configurable deployment of embedded transducers into a structure. Further applications include instrumentation for jet turbines and Flight Control Systems, oil exploration, marine structures and nuclear power plants requiring real-time control and monitoring, and critical infrastructure monitoring for homeland security.

The proposed project has direct NASA applications in the following areas regarding aerospace vehicles and structures: o Automated Nondestructive Evaluation of fault development in structural components: o Integrated Vehicle Health Monitoring (IVHM) o Flight control System Real-time autonomous sensor validity monitors o Monitor statistical manufacturing, assembly process and control; internal temperature and pressure monitoring of composite materials during the curing process; composite bonded repairs; sandwich structures; gun barrel; reusable launch vehicles; burst testing of pressure vessels and tanks; aero propulsion flight tests o Self-monitoring structures with alarm and abort capabilities