Abstract
A theoretical analysis of the consideration of the effect of the attenuation of adhesion materials was studied in order to raise the reliability of non-destructive evaluations of adhesion layer thickness using the ultrasonic Lamb wave. The analysis results were well in agreement with the experimental results. Good concurrence was obtained about the correlation of phase velocity and adhesion layer thickness, and correlation of the derivation frequency of higher order mode waves and adhesion layer thickness. It was explained theoretically that the derivation frequency of the wave of higher order mode becomes low with the increase in adhesion layer thickness.
