Air-coupled ultrasonic transducers are used to generate and receive Lamb waves in quasi-isotropic laminated composite beams for delamination detection. The influence of incident angle on the excited mode is studied. N...Air-coupled ultrasonic transducers are used to generate and receive Lamb waves in quasi-isotropic laminated composite beams for delamination detection. The influence of incident angle on the excited mode is studied. Numerical calculation and experimental results show that a pure Lamb wave mode can be generated if the transmitting transducer is oriented at a specific angle, and the receiving transducer can either be oriented to detect the same mode as that generated by the transmitter or to detect another mode generated by mode conversion at a defect. A three-dimensional finite element model is created to predict the interaction of Lamb waves with delamination, and some unique mechanisms of interaction between A0 mode Lamb waves and delamination are revealed in detail. The experimental results obtained on laminated composite beam using air-coupled ultrasonic transducers are well in accordance with finite element simulation results. Research results show that air-coupled ultrasonic guided waves can be used for delamination damage detection effectively in laminated composite beams.展开更多
基金supported by the National Natural Science Foundation of China(Grant Nos. 11272021 and 50975006)Beijing Natural Science Foundation(Grant No. 1122007)+1 种基金the Importation and Development of High-Caliber Talents Project of Beijing Municipal Institutions(No.CIT&TCD201304048)Beijing Nova Program(Grant No. 2008A015)
文摘Air-coupled ultrasonic transducers are used to generate and receive Lamb waves in quasi-isotropic laminated composite beams for delamination detection. The influence of incident angle on the excited mode is studied. Numerical calculation and experimental results show that a pure Lamb wave mode can be generated if the transmitting transducer is oriented at a specific angle, and the receiving transducer can either be oriented to detect the same mode as that generated by the transmitter or to detect another mode generated by mode conversion at a defect. A three-dimensional finite element model is created to predict the interaction of Lamb waves with delamination, and some unique mechanisms of interaction between A0 mode Lamb waves and delamination are revealed in detail. The experimental results obtained on laminated composite beam using air-coupled ultrasonic transducers are well in accordance with finite element simulation results. Research results show that air-coupled ultrasonic guided waves can be used for delamination damage detection effectively in laminated composite beams.
