Lightweight structural components operating in high-temperature environments—such as disks, aerospace panels, and thermal protection systems—must maintain stability under thermally induced stresses. In such applications, thermal buckling becomes a critical design concern, particularly when advanced composite sandwich structures are employed. In this study, the thermal buckling behavior of annular sandwich plates incorporating an architected auxetic core and three-phase nanocomposite face sheets is investigated. The mechanical formulation is developed using Murakami’s zig-zag theory to accurately capture layerwise deformation effects, while the governing equilibrium equations are derived through the principle of virtual displacements. The resulting system is solved numerically using the generalized differential quadrature method, and the interaction with a nonuniform (radially graded) elastic foundation is also incorporated to represent realistic support conditions. The reliability of the formulation is verified through comparison with available reference solutions and convergence analyses. Parametric investigations reveal that increasing the auxetic core thickness significantly enhances thermal stability by improving the bending rigidity of the sandwich structure. The architected auxetic cell geometry is also shown to play a key role, where larger cell angles and taller cellular configurations noticeably increase the critical thermal buckling temperature. Furthermore, the presence of a radially graded elastic foundation is found to substantially improve structural stability, especially when both the baseline stiffness and the stiffness gradient are sufficiently large. The results demonstrate that the thermal buckling performance of auxetic-core sandwich structures is governed by a complex interaction between material composition, cellular architecture, and support conditions, providing useful design insights for advanced thermally loaded engineering systems.
Arshid et al. (Thu,) studied this question.