Thermoelastic stress analysis of functionally graded material beams under pulsed thermal loads using GN-III theory

In this paper, the transient thermoelastic response of Functionally Graded Material (FGM) beams under pulsed thermal loading is studied based on the Green–Naghdi Type III (GN-III) thermoelasticity theory. An implicit finite difference numerical model is developed in MATLAB to investigate the transient temperature change, finite-speed thermal-wave propagation, thermoelastic stress generation, and displacement response for non-Fourier heat conduction. The proposed numerical formulation includes power-law material gradation, thermal relaxation, and thermo-mechanical coupling in order to offer a physically consistent representation of transient thermoelastic behaviors. A comparative study between the GN-III model and the classical Fourier heat conduction theory is carried out to study the effect of thermal relaxation and finite thermal-wave propagation on the beam response. The outcomes show delayed thermal-wave propagation and a slower temperature evolution than the classical Fourier model, implying that non-Fourier heat conduction is important. The numerical stability, accuracy, and mesh independence of the proposed framework are validated by mesh convergence. Overall, it is concluded that the developed model is an effective and reliable physical model that can be used to predict the transient thermo-mechanical behavior in advanced functionally graded structures.