Observation of the Impact of Defect on Wedge Waves by Laser Ultrasound Technique

The research focuses on measuring the influence of defect on wedge waves by using laser ultrasound technique. The wedge waveguide models with defect and different angles were built and calculated by using finite element method. Both reflected and transmitted waves are observed. Meanwhile, angle has the greatest influence on the low-order wedge wave mode, and there is low order reflected wave and transmitted wave modes separate from high order mode. By integrating the power spectra of the wedge waves, the energy distribution of these wedge waves of 20°, 30°, 45° and 60° wedge are analyzed, and the location of defect is determined. The results of this study can provide theoretical guidance for the positioning and size estimation of wedge defects.