The effect of the triple periodic minimum surface materials on the thermomechanical buckling of sandwich plates with hybrid face layers

This study investigates the thermal buckling behavior of sandwich plates with triply periodic minimal surface (TPMS) cores and functionally graded Ni–ZrO2 hybrid face layers under nonlinear through-thickness temperature fields. A newly implemented hyperbolic sinusoidal higher-order shear deformation theory is employed to calculate the critical thermal buckling loads of three TPMS topologies: TPMS-I, TPMS-II, and TPMS-III. The effects of core topology, solid fraction, metal–ceramic gradation, face-layer void ratio, characteristic length, thermal expansion mismatch, and temperature difference are evaluated under identical geometric and boundary conditions. The results show that thermal buckling stability is governed by the combined influence of topology, material distribution, and scale effects. Increasing the solid fraction, metallic phase content, and characteristic length improves the critical buckling resistance, whereas increasing the void ratio, temperature difference, and thermal expansion mismatch reduces it. TPMS-II provides efficient stiffness and stable performance at low-to-moderate densities, while TPMS-III offers superior thermal endurance and structural stability at higher densities and metal fractions. Although the responses of the three topologies partially converge under severe thermal loading, the overall performance hierarchy remains TPMS-III ≈ TPMS-II > TPMS-I, confirming the dominant role of core topology in thermomechanical stability.