Optimal Realtime Damage Identification in Composite Structures

Intelligent Fiber Optic Systems Corporation (IFOS) proposes to develop an effective real-time, in situ damage locating and growth monitoring system of composite structures by optimizing a smart, high-speed fiber Bragg grating (FBG) sensor and piezoelectric actuator placement strategy. A new damage identification technique is proposed from which damage in composites such as delamination and impact-related defects can be detected. The proposed technique utilizes the pitch-catch Lamb wave signals obtained from an FBG sensor and piezoelectric actuator network, without the need of baseline signals from the pristine condition. The project goals include designing an ultra-high-speed/high resolution, small footprint FBG sensor and piezoelectric actuator network plus an FBG interrogator, constructing a system model, fabricating a test platform and developing signal processing algorithms to identify and measure Lamb wave signals in the presence of a quasi-static background strain field. The system model will demonstrate proof-of-principle, and the test results will provide proof-of-functionality of the proposed sensor system as a measurement method for damage identification in composite structures. The methodology proposed by IFOS includes using advanced signal processing algorithms. IFOS and its collaborators in this project will develop a Phase II plan that includes a development and integration strategy, potential demonstration opportunities, program schedule, and estimated costs.