Leaky Interface Wave Measurement at a Solid-Solid Interface with Laser Ultrasonics

The experimental investigation on transparent solid/solid (aluminum and plexiglas) interface leaky waves generated by a pulse laser and detected with a photoelastic effect technique is reported. Three waves, i.e., longitudinal head wave, leaky Rayleigh wave and leaky interface wave, are detected successfully. The leaky waves propagating along the 'weak bonding' interface are also measured. It is found that with the continuing epoxy solidification, the wave amplitude gradually decreases and the two leaky waves are more difficult to distinguish. The velocities of the detected interface wave are in good agreement with the theoretical calculation and the attenuation characteristics of the two leaky waves are also in accordance with the theoretical prediction.