Study on effects of viscoelastic moduli on similar Rayleigh waves propagation in metal -adhesive coating structures

In order to understand the viscoelastic characteristics of the coatings and evaluate adhesive quality, the study of the half-infinite metal -adhesive coating structures on similar Rayleigh waves is carried through. Based on the general viscoelastic theory, the characterization frequency equations are founded by means of the Laplace-Hankel transform method. Considered coatings as Kelvin model, the effect on frequency dispersion and attenuation related to viscoelastic moduli are analyzed. It shows that the viscosity offers only little effect on lower mode of dispersion curve, and it effects on higher mode of dispersion curve with the increasing of damping. Besides, the viscosity gives much influence on attenuation, it is found the Sezawa mode presents more sensitivity than Saw mode, especially its attenuation will show a local minimum in some case. The results of the simulation show that the study of the viscoelastic characteristics of the coatings could provide some theoretical way for estimation of viscoelastic parameters or evaluation of adhesive quality.