WAVE PROPAGATION IN PIEZOELECTRIC MEDIUM WITH THE FLEXOELECTRIC EFFECT CONSIDERED

With the consideration of the flexoelectric effect, the dispersion feature of plane waves propagating in infinite piezoelectric medium and the reflection amplitude ratio at a mechanically traction-free and dielectrically charge-free surface of semi-infinite piezoelectric half-space are studied in this paper. The flexoelectric effect is essentially the microstructure effect of heterogeneous piezoelectric medium. Besides, the strain gradient effect and the micro-inertial effect are also introduced to reflect the influences of the microstructure. Different from the classical piezoelectric medium, there are five kinds of coupled elastic waves in the microstructured piezoelectric medium. The influences of the flexoelectric effect, the strain gradient effect and the micro-inertial effect upon the dispersion feature of the coupled elastic waves and the reflection amplitude ratio are studied numerically. The numerical results are shown graphically and are validated by the energy conservation law. It is found that these microstructure effects have obvious influences upon the dispersion feature of the coupled elastic waves and therefore also affect the reflection energy partition at the mechanically free surface. Especially, the micro-inertial effect has fundamental influences on the dispersion properties of the coupled elastic waves.