An analysis of angled surface-breaking crack detection by dual-laser source generated ultrasound

摘要

The propagation and scattering of ultrasound generated in a cracked specimen detected by anevaluating system with a dual-laser source has been studied by using finite element method (FEM). Thevarious ultrasonic modes are analyzed in detail, and a method for calculating the crack-orientationangle is presented by employing the propagating times of scattered ultrasonic modes. Correspondingexperimental system is then built. The arrival time of scattered ultrasonic modes propagating in twocracked aluminium specimens are measured by using the method provided and crack-orientationangles are calculated. Results from numerical simulation and experiment are compared, the accuracy ofthe method is proved accordingly.