Effects of interface bonding on acoustic wave generation in an elastic body by surface-mounted piezoelectric transducers

We study the effects of interface bonding on acoustic wave generation in an elastic body using surfacemounted piezoelectric transducers driven electrically. A theoretical analysis is performed based on a physical model of a piezoelectric layer on an elastic substrate. The transducer-substrate interface is described by the shear-slip model, representing a viscoelastic interface. Different from the results in the literature on free vibrations of structures with weak interfaces, this paper presents an electrically forced vibration analysis. An analytical solution for the generated acoustic wave is obtained and used to calculate its energy flux and the efficiency of the transduction. The effects of the interface parameters are examined. It is found that the interface bonding affects the performance of the transducer in multiple ways, some of which may be exploitable in designs for better transducer performance. In particular, optimal transduction is not necessarily associated with a perfectly bonded interface.