Surface wave scattering by a material interphase between two edge bonded plates

Abstract

Reflection and transmission of surface waves at a material interphase between two edge bonded composite plates have been investigated in this paper. The study is motivated by the need to develop a quantitative ultrasonic technique to characterize properties of joints between two plates which may be laminated and anisotropic. Although there have been some recent studies that have examined the reflection and transmission of surface waves at the interphase between two plates, they consider the plates to be semi-infinite in thickness. Thus the mode conversion of surface waves into higher guided modes of the plates are not taken into account. In this paper we show that at high frequencies when a 0 and S 0 modes tend to become surface waves, the interaction of these waves with the joint interphase gives rise to higher modes, the effect of which is seen as resonant peaks in the reflection and transmission coefficients at the cutoff frequencies of these modes. These peaks become increasingly pronounced as the thickness of the interphase increases. Another interesting feature is that the reflection coefficient becomes minimum at a frequency that depends on the thickness and the properties of the interphase material. These features can be used to determine the relevant properties of the joint.