Thermal-structural dynamic behaviors of a beam under non-Fourier thermal shock: Theorical and numerical analysis

A coupled thermal-structural dynamic model of a beam under non-Fourier thermal shock and its approximate solution are developed in the present study. Meanwhile, the analytical solution for thermally induced vibration (TIV) of a beam without thermal structural coupling effects is also derived. The thermal relaxation ratio (i.e., the ratio of thermal relaxation time to the thermal characteristic time of the structure) is introduced to represent non-Fourier effect. The effects of inertia parameter, rotational inertia parameter and thermal relaxation ratio on TIV behaviors are studied. Results indicate that the beam with specific thermal relaxation ratio and inertia parameter will exhibit unique “resonance” phenomenon, where structural frequencies are close to the thermal bending moment variation. Furthermore, the influencing factors of thermal flutter (TF) are also explored, including thermal relaxation ratio, heat flux incident angle, uncouple absolute rotation angle, and boundary conditions. It is found that TF stability is not related to non-Fourier effect. The larger difference between the heat flux incident angle and the quasi-static rotation angle implies better TF stability. This work enhances the understanding of the non-Fourier effect and its role in thermal-structural dynamic behaviors, extending beyond Fourier-based models.