Ultrasonic testing is effective in defect characterization and quality assurance of Carbon Fiber Reinforced Plastic(CFRP) components in the aerospace industry. Due to the coupling between complex shape and elastic ani...Ultrasonic testing is effective in defect characterization and quality assurance of Carbon Fiber Reinforced Plastic(CFRP) components in the aerospace industry. Due to the coupling between complex shape and elastic anisotropy, the Phased Array Ultrasonic Testing(PAUT) and time-based Total Focusing Method(TFM) face significant challenges in the calculation of wave propagation. A wave velocity distribution model is established for a multidirectional convex corner of CFRP based on a homogenization theory and the above coupling effects are also incorporated. A ray-tracing method is proposed based on Dijkstra’s shortest path search algorithm. The predicted time of flight ensures that this technique, the homogenized TFM, could synthesize a high-quality focused image by post-processing on the full matrix capture data. Experiments on a laminate with three φ1.5 mm Side-Drilled Holes(SDHs) in different circumferential directions confirm a successful homogenized TFM imaging that all SDHs can be effectively detected. As compared to the isotropic scenario, the maximum positioning error is reduced to 0.12, 0.08, and 0.38 mm, and the Signal-to-Noise Ratios(SNRs) are increased by 2.1, 1.1, and 11.8 dB, respectively. It is suggested that the ray-tracing assisted TFM technique can effectively improve the imaging of corners in CFRP components.展开更多
基金supported by the Fundamental Research Funds for the Central Universities,China(No.DUT22GF304)the Dalian Support Plan for Innovation of High-Level Talents(Youth Science&Technology Stars)+2 种基金China(No.2018RQ40)the Liaoning Revitalization Talents Program,China(No.XLYC1902082)the National Basic Research Program of China(No.2014CB046505).
文摘Ultrasonic testing is effective in defect characterization and quality assurance of Carbon Fiber Reinforced Plastic(CFRP) components in the aerospace industry. Due to the coupling between complex shape and elastic anisotropy, the Phased Array Ultrasonic Testing(PAUT) and time-based Total Focusing Method(TFM) face significant challenges in the calculation of wave propagation. A wave velocity distribution model is established for a multidirectional convex corner of CFRP based on a homogenization theory and the above coupling effects are also incorporated. A ray-tracing method is proposed based on Dijkstra’s shortest path search algorithm. The predicted time of flight ensures that this technique, the homogenized TFM, could synthesize a high-quality focused image by post-processing on the full matrix capture data. Experiments on a laminate with three φ1.5 mm Side-Drilled Holes(SDHs) in different circumferential directions confirm a successful homogenized TFM imaging that all SDHs can be effectively detected. As compared to the isotropic scenario, the maximum positioning error is reduced to 0.12, 0.08, and 0.38 mm, and the Signal-to-Noise Ratios(SNRs) are increased by 2.1, 1.1, and 11.8 dB, respectively. It is suggested that the ray-tracing assisted TFM technique can effectively improve the imaging of corners in CFRP components.
