Nonlocal thermoelastic modeling of fiber-reinforced composites: Integrating MGT and length-scale effects

This study introduces a novel nonlocal thermoelastic model that enhances the Green-Naghdi Type III (GN-III) framework by incorporating the Moore-Gibson-Thompson (MGT) equation and nonlocal length-scale effects. The proposed model is used to analyze the thermoelastic behaviour of fiber-reinforced composites. By addressing limitations of classical thermoelasticity, such as instantaneous thermal wave propagation, the model incorporates thermal relaxation to ensure finite-speed thermal wave propagation. A case study of an infinite fiber-reinforced medium with a traction-free cylindrical cavity under harmonic thermal loads employs the Laplace transform for analytical solutions, validated through numerical simulations. Key contributions include improved modeling of anisotropic fiber effects and thermal damping, offering superior accuracy over classical models like Fourier’s law and Lord-Shulman. Numerical results demonstrate significant reductions in temperature and displacement, alongside amplified radial stress, indicating enhanced predictions of thermal and mechanical responses. Compared to nonlocal operator methods, this model excels in capturing time-dependent thermomechanical behavior, though it is limited by linear assumptions. These findings are significant for applications in aerospace (e.g., heat shields), automotive (e.g., chassis), and structural engineering (e.g., pressure vessels), where precise thermal and stress management is critical. Future work will focus on experimental validation and extending the model to nonlinear and finite-domain scenarios to enhance its practical utility.