The theory of shear horizontal wave scattering processes in layered piezoelectric composites is discussed in terms of a recursive system of equations involving the piezoelectric impedance. Piezoelectric materials of hexagonal 6 mm symmetry are considered. The behavior of an incident shear horizontal piezoelectric wave is analyzed as a function of the material properties, layer thicknesses, and frequency (omega). By an appropriate choice of the materials and layer thicknesses, frequencies at which almost all energy is transmitted can be found, optimizing the properties of the system for ultrasound transducers. This behavior is also dependent on the incident angle. Furthermore, most laminated materials are bonded using polymers. We show that adding these polymers hampers the response of the piezoelectric laminated system, localizing the transmission at particular incident angles. Thus, sharp spikes of ultrasonic pulses could be generated with these laminated structures. (C) 2001 American Institute of Physics. References: 17
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