Transmission of SH waves through an elastic layer between two solids with frictional contact interfaces

The propagation of SH waves in a three-layered medium containing an interla yer between two semi-infinite solids with frictional contact interfaces is studied. The incident wave, which propagates through the layer from one hal f-space to another with subcritical angle, is assumed to be strong enough s o that friction may be broken, and the local slip may take place at the int erfaces. The mixed boundary conditions involving inequalities and unknown i ntervals lend to a set of recurrence relations. Special examples are given for the case of identical materials to illustrate the mathematical procedur e to obtain final results. The interface tractions and relative slip veloci ties are presented. The interaction between the two interfaces is discussed . It is shown that the slip of the interface near the incident wave may res train the slip of the interface far from the incident wave, while that the latter may facilitate the former We also find the instability of the system for similar values of the two interface friction coefficients. Finally, th e energy transmitted through the interlayer and dissipated by the friction of the two interfaces are examined.