Numerical Study for Surface-breaking Crack Detection on a Cylinder Using Laser-generated Ultrasound

Laser ultrasonic has been widely investigated for its high spatial resolution, non-contact generation and distant testing. In this study, the laser induced waves on a cylinder is simulated based on an explicit finite element model, and the location of the surface-breaking crack is determined using signal enhancement of surface waves on the cylinder. A feature is extracted based on wavelet packet transform and singularity value decomposition (WPT-SVD) to gauge the depth of surface-breaking crack. The simulation results show that the feature is sensitive to the surface-breaking crack, with an accurate location determined by an enhancement of surface waves when the crack is close to the laser source. This study provides a potential application for testing surface-breaking cracks on the rotating cylindrical component.