Wave reflection by the free boundary of a microstructured flexoelectric half-space

Abstract

Taking into consideration the effects of micro-inertia, flexoelectricity, and non-uniform strain, the field equations of isotropic dielectrics with centrosymmetric microstructures are specialized for a plane. Plane-wave solutions of these two-dimensional (2D) governing equations suggest the possibility of two plane waves propagating in a flexoelectric medium. Reflection phenomenon of the plane harmonic waves from the stress-free boundary of a dielectric half space is explored. The expressions for the coefficients of reflection and energy shares of reflected waves are obtained for the cases of both incident plane waves. The relevant physical constants of strontium titanate are chosen for numerical computations of the speeds, coefficients of reflection and energy shares of reflected waves. These wave characteristics are illustrated graphically to show the influences of incident angle, wavenumber, length parameter, and flexocoupling coefficient.

Keywords:

• Flexoelectricity
• strain gradient elasticity
• centrosymmetry
• microstructure
• reflection coefficients
• energy ratios