State Space Approach to Characterize Rayleigh Waves in Nonlocal Thermoelastic Medium with Double Porosity under Three-Phase-Lag Model.

The present article focuses on the Rayleigh surface wave propagation in homogeneous isotropic thermoelastic medium. This works aims to develop a new nonlocal elasticity model based on three-phase-lag model of hyperbolic thermoelasticity under double porosity structure. New constitutive relations and equations are derived using nonlocal continuum mechanics. State space approach is employed to solve the problem. Frequency equation is derived using appropriate boundary conditions. Path of surface particles is found elliptical at the time of Rayleigh surface wave propagation. Different characteristics of Rayleigh waves are calculated numerically and presented graphically for different wave number. Various characteristics of wave for different thermoelastic models are also presented graphically. The effect of nonlocal parameters and void parameters on phase velocity, attenuation coefficient, penetration depth, and specific loss of Rayleigh waves are shown graphically. Some special cases are deduced from this study which agree with the existing literatures. [ABSTRACT FROM AUTHOR]