Reflection of time‐harmonic thermoelastic waves in an initially stressed nonlocal fiber‐reinforced orthotropic composite under DPL model

The present study investigates the reflection of plane waves from the free surface of an initially stressed nonlocal fiber‐reinforced orthotropic thermoelastic composite half‐space within the framework of dual‐phase‐lag (DPL) theory. Three coupled plane waves with distinct speeds are found to propagate through the medium. The reflection phenomena at the stress‐free surface is investigated, considering appropriate boundary conditions. The explicit form of the expressions for the amplitude and energy ratios of the reflected coupled plane waves are derived. Numerical computations for a magnesium‐like crystal are performed using MATLAB software, with the results are visualized and interpreted through graphs. Initial stress, generalized theories, nonlocal parameter and material's anisotropy due to different levels of fiber‐reinforcement significantly affect the amplitude ratios of the reflected waves. It is verified that, during reflection phenomena, there is no dissipation of energy i.e. the sum of energy ratios equals unity at each incident angle.