Numerical Simulation of Metal Defect Detection Based on Laser Ultrasound

The noncontact and wide-band characteristics of the ultrasonic signal excited by laser make it widely used in nondestructive detection. In this paper, finite element method is to simulate multiple modes responses them metal defects. simulation shows that changes Rayleigh-wave (RW) shear-wave (SW) can be research surface crack internal defect sample respectively. By analyzing reflected wave RW SW at inspection point, effects on signals two are quantitatively compared. results show time delay Rayleigh echo has a linear relationship width transverse position crack, peak-valley difference point depth also fitted linearly. addition, Y component displacement bottom decays with change defect. This model provides theoretical basis for further experimental verification basis.