Acoustic wave behavior in rotating functionally graded piezomagnetic media with impedance boundaries

Abstract

This study examines the reflection characteristics of coupled waves in a functionally graded piezomagnetic medium, incorporating rotational dynamics and impedance boundary conditions. A comprehensive theoretical framework is developed by integrating flexomagnetic coupling, strain gradient elasticity, micro-rotational inertia, and spatial material gradation. The surface is modeled with impedance-type boundary conditions to simulate realistic interface behaviors. A secular equation governing wave motion is derived, and the reflection characteristics of five distinct coupled wave modes are analyzed in terms of energy ratios, dispersion relations, and incidence angle variations. Numerical simulations demonstrate that both rotation and impedance boundaries significantly influence the redistribution of energy among reflected waves, while functional grading enhances anisotropic responses. The presence of rotational motion alters the dynamic coupling between wave modes, and impedance boundaries introduce partial energy absorption and phase shifts, offering refined control over wave propagation. These findings are especially relevant for designing advanced sensors, actuators, and surface acoustic wave (SAW) devices in magneto-electro-elastic systems. The study contributes a novel wave reflection framework by integrating functionally graded properties, rotational effects, and boundary impedance, offering new insights into energy transfer mechanisms under complex material and boundary conditions.