Phased-Array Laser Ultrasonic Testing with Sparse Total Focusing Imaging Method

Abstract

In order to further improve the detectability of laser ultrasonic testing method for internal defects of materials, this paper studies a new phased array laser ultrasonic detection and imaging method based on the full matrix capture technology and total focusing method. Based on the finite element method, a numerical model of full matrix laser ultrasonic detection and signal sampling is developed to acquire the signal data of full matrix laser ultrasonic testing, and then the corresponding program of the total focusing method algorithm is developed to realize the visual imaging detection of different defects in the specimen based on the total focusing method. Subsequently, in order to improve the efficiency of laser ultrasonic testing with full matrix phased array, a full matrix laser ultrasonic testing method with sparse array is proposed, and a signal reproduction method based on sparse array is developed to expand sparse array to dense array signal, thus achieving high quality imaging of internal defects, and effectively improving the detection efficiency of this method.