Investigation of the thermomechanical buckling characteristics in auxetic sandwich dome structures featuring metal–ceramic composite face layers

This research examines the thermomechanical buckling behavior of the sandwich dome structures composed of an auxetic cellular core and metal–ceramic composite face sheets. Various dome geometries—including cylindrical, spherical, hyperbolic, and elliptic paraboloid configurations—are analyzed. The structures are modeled using a high-order shear deformation theory (HSDT) within the framework of an equivalent three-layer plate formulation. The research primarily focuses on assessing how the geometric parameters of the auxetic core and the metal-to-ceramic ratio in the face layers influence the thermo-mechanical buckling response. The governing equations are derived using Hamilton's variational principle, and the Navier solution method is employed for buckling analyses. The results reveal that the buckling performance of the sandwich dome is highly sensitive to both the core geometry and the material distribution in the face layers. Notably, for fully clamped boundary conditions, increasing the rib inclination angle (θ) from 15° to 60° leads to a ∼41% reduction in the non-dimensional critical thermal buckling load, while raising the critical buckling temperature by approximately 18%. These findings highlight the necessity of optimizing both geometric and material parameters in the design of auxetic-core sandwich domes subjected to thermal loads.