Wave reflection and refraction in rotating and initially-stressed piezoelectric crystals

The purpose of this paper is to address the wave reflection and refraction in the rotating piezoelectric crystals subjected to a biaxial, homogeneous stress field. Besides, utilizing the inhomogeneous wave theory enables additional reflected and refracted surface waves to solve the problem of discrepancy between independent wave modes and boundary equations. A set of homogeneous equations in displacements and electric potential is derived within the rotatory coordinate system in the presence of the Coriolis and centrifugal acceleration. The performed plane example shows that there is a critical point when angular velocity equals the wave frequency, at which no quasi-longitudinal wave can be generated, reflected or refracted, and close to which the characteristics of the quasi-longitudinal wave change sharply. In addition, the presence of the Coriolis and centrifugal accelerations demonstrates noticeable influence upon the wave propagation and reflection/refraction, namely the wave velocities and attenuations, the angles of the reflected/refracted bulk waves, the reflection/refraction amplitudes and energy ratio coefficients. The analysis results also indicate that the reflected and refracted waves can transform into the type of surface wave at some incident angles. Finally, compared with the rotation effects, the waves are not sensitive to the initial stresses.