Evaluation of Composite Matrix Crack Using Nonlinear Ultrasonic Lamb Wave Detected by Fiber Bragg Grating
WANG Rong 1, 2 , WU Qi 2 , XIONG Ke 2 , ZHANG Hanqi 2
1. Nanjing Vocational University of Industry Technology, Nanjing 210023, China;
2. State Key Laboratory of Mechanics and Control of Mechanical Structures, Nanjing University of Aeronautics and Astronautics, Nanjing 210016, China
Abstract：A high-sensitive and broad-bandwidth phase-shifted fiber Bragg grating based ultrasonic detection system with proportional-integral-derivative feedback controller was proposed to evaluate the ultrasonic nonlinearity induced by the matrix crack in carbon fiber reinforced plastic. After the optical fiber sensing system detected the ultrasonic Lamb wave propagating in a composite laminate, the second harmonic components with a frequency of 2.0MHz was extracted from Lamb wave signals by data processing. The result show that the relative nonlinear parameter grew linearly with the increase of crack numbers. In comparison with conventional lead zirconate titanate sensor, the relative nonlinear parameter detected by the phase-shifted fiber Bragg grating sensor shows a higher growth rate. Thus, the proposed fiber optic-ultrasonic detection system with high reliability can be applied to the evaluation of matrix cracks damage of composite materials.
2021, 
