Memory Effects in Anisotropic Viscothermoelastic Media: A Three Phase Lag Model Analysis

This study investigates the impact of memory on anisotropic visco-thermoelastic media using a novel three-phase-lag (3PHL) model. The Fourier–Laplace transform is applied to obtain the characteristic equations for phase velocity, specific loss, attenuation coefficient, and penetration depth of viscous waves. The validity of the proposed model is evaluated by comparing it with previously published results. The outputs show the coupling between phase velocity, specific loss, attenuation coefficient, and penetration depth changes with time delay parameters, illustrating the effect of memory in this 3PH model. A thorough analysis of the linear kernel function was also conducted. Additionally, the presence of several kernel functions reveals significant differences in this visco-thermoelastic medium. Numerical calculations were performed on poly-methyl material due to its high thermal conductivity, low thermal expansion coefficient, high glass transition temperature, and good creep resistance. Mathematica software is used to generate two-dimensional and three-dimensional graphical results. The author believes that this study will be useful for wave-based technologies such as ultrasonic devices and energy harvesting technologies to design more efficient models.