Ultrasonic Lamb Wave Array Technique for Damage Defection in Plates

To detect the defects in the plates,based on the study of the multi-modes and frequency dispersion of guided wave in the plate,the dispersion curves were got by calculation,and the transducers which can generate lamb wave were designed. Multiple transducers were laid out in circular sensor array,and many groups of signal were rapidly collected through the multi-channel ultrasonic testing and imaging system. The experiment detecting the artificial defects in the plate based on ellipse orientation imaging technique,shows that the system can effectively distinguish the position and orientation of artificial defects from the images.