Lattice-core sandwich panels (LCSPs) with fabricated by additive manufacturing have attracted extensive interest stemming from their exceptional mechanical properties and multi-functionalities. Nevertheless, the direct correlation among stress distributions in sandwiches, external loads, and ambient environments remains unclear. This study develops an analytical predictive model capable of efficiently capturing the mechanical response of LCSPs under various temperatures. The equivalent elastic modulus of lattice cores with different unit-cell aspect ratios is first determined according to finite element (FE) results. Subsequently, the thermo-mechanical field of the homogenized sandwich in various ambient temperatures is analytically predicted based on the higher-order shear deformation theory. Finally, truss stresses within lattice cores are directly calculated using an effective displacement transition method. The prediction exhibits outstanding consistency with FE simulations. Furthermore, the impact of several key variables on the truss stress distribution is demonstrated based on parametric analysis. The results reveal that the vertical truss is the main object of bearing the major uniaxial compressive load within the body-centered cubic (BCCZ) and vertically reinforced face-centered cubic (F2CCZ) lattice cores. The increased transverse layer number/power index and/or the smaller length-to-thickness ratio contribute to a significant reduction in inclined/vertical truss stresses. In contrast, the elevated longitudinal layer number, ambient temperature, and thermal expansion of face sheets result in stress accumulation. Furthermore, the stress distributions in BCCZ LCSPs are commonly higher than those within F2CCZ LCSPs. These results can provide a useful path for the design and fabrication of additively manufactured sandwich panels with desired mechanical properties.
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