SURFACE-WAVE SCATTERING BY A MATERIAL INTERPHASE BETWEEN 2 EDGE BONDED PLATES

Reflection and transmission of surface waves at a material interphase between two edge bonded composite plates have been investigated in thi s 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 bee n some recent studies that have examined the reflection and transmissi on of surface waves at the interphase between two plates, they conside r the plates to be semi-infinite in thickness. Thus the mode conversio n of surface waves into higher guided modes of the plates are not take n into account. In this paper we show that at high frequencies when A0 and S0 modes tend to become surface waves, the interaction of these w aves 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 bec ome increasingly pronounced as the thickness of the interphase increas es. Another interesting feature is that the reflection coefficient bec omes minimum at a frequency that depends on the thickness and the prop erties of the interphase material. These features can be used to deter mine the relevant properties of the joint.