Scattering of SH‐Waves From an Elliptical Defect at the Interface of Piezoelectric Bilayers

ABSTRACT

This work investigates the scattering of anti‐plane shear (SH) waves by an elliptical defect located at the interface of two transversely isotropic piezoelectric layers. We construct a Green's tensor specifically designed for piezoelectric bilayer media by solving non‐homogeneous partial differential equations with homogeneous boundary conditions. The boundary value problem is reduced to a coupled system of boundary integral equations using the reciprocal work theorem and generalized Green's identity. These equations are then discretized via the boundary element method to compute displacement fields and electric potentials along the contour of the void. Finite element simulations complement the boundary element solutions, providing a three‐dimensional visualization of the electromechanical fields. The results show a significant concentration of displacement at the void poles and with magnitudes increasing proportionally with void size. Notably, a significant asymmetry in the displacement fields between the upper and lower layers (asymmetry ratio ) serves as a powerful indicator for identifying interfacial defects, distinguishing them from buried voids in homogeneous media. Additionally, electric potential distributions indicate strong electromechanical coupling, with potential gradients enhanced by a factor of 2.1 to 2.6 near the cavity. These quantitative metrics establish a foundation for non‐destructive evaluation of layered piezoelectric structures through dual‐modality inspection strategies that combine mechanical and electrical field measurements.