Effects of Coulomb friction, gravity, and magnetoelastic coupling on Rayleigh waves in a reinforced layered composite structure

Rayleigh-type waves are highly sensitive to the mechanical and interfacial properties of layered media, making their study important for characterizing composite structures and geophysical materials. The present paper investigates the characteristics of Rayleigh wave propagation in a magnetoelastic fibre-reinforced layer overlying a pre-stressed magnetoelastic fibre-reinforced orthotropic half-space under gravity. The main contribution of this study is the development of a unified analytical framework that simultaneously incorporates magnetoelasticity, fibre reinforcement, orthotropy, initial stress, gravity, and a Coulomb-friction interface. An analytical approach, the method of separation of variables, is used to obtain displacement fields, and the corresponding dispersion relation is derived using appropriate boundary conditions. Some limiting cases are also discussed to recover the classical Rayleigh wave equation and to validate the proposed formulation. Numerical results computed in MATLAB using parameter values from the existing literature illustrate that the Rayleigh wave phase velocity is significantly affected by the initial stress, gravity, electromagnetic and magnetoelastic parameters, fibre-reinforcement parameters, and interfacial bonding conditions. The results show that interfacial friction plays a significant role in modifying Rayleigh wave characteristics, emphasizing the importance of imperfect interface modelling in layered composite and geophysical media. This study provides valuable insights into wave propagation in complex frictionally bonded composites, offering useful information for engineering applications.