Laser ultrasonic testing for inspection of curved surface samples based on synthetic aperture focusing

Abstract Synthetic Aperture Focusing (SAFT) is one of the methods to improve the spatial resolution in laser ultrasound. However, the research on laser ultrasonic SAFT technology is mainly focused on block or plate samples. In order to study the detection capability of laser ultrasonic SAFT technology on the samples with curved surface, a finite element simulation model of curved surface samples with sub millimeters internal defects is established. And then the laser ultrasound field is obtained through numerical simulation. At last the SAFT algorithm was performed to image the defects in the samples. The results show that laser ultrasonic SAFT technology can image curved surface samples with sub millimeters internal defects. The results provide a reference for the practical application of laser ultrasonic SAFT technology.