Laser Ultrasonic Nondestructive Testing Based on Nonlinear Ultrasonic Coefficient
Feng Qin, Yaojin Wu, Hualing Guo, Bin Zheng, Hui Liu
Abstract
Laser ultrasonic nondestructive testing technology can effectively detect the location of cracks and other information, it is easy to realize the qualitative detection of cracks, but it is difficult to achieve quantitative detection of cracks. In this paper, based on the traditional nonlinear ultrasonic method, ultrasound excited by laser. Combining the characteristics of laser ultrasonic waveform, the nonlinear ultrasonic coefficient of laser and the nonlinear ultrasonic model of laser are deduced. Through the establishment of experimental samples, the transmission and reflection of two ways to experiment were conducted, the experimental data are processed by nonlinear coefficients of laser ultrasonic, obtaining the relationship between coefficient and the depth of the crack, and the results are compared with the simulation data, The results show that the laser nonlinear ultrasonic model can support the nonlinear ultrasonic coefficients of the laser, and the laser nonlinear ultrasonic can represent the depth of the crack to a certain extent and realize the quantitative detection of the crack.