ShashirajPitchaimani, J.Kattimani, S.2026-02-032025Composite Structures, 2025, 372, , pp. -2638223https://doi.org/10.1016/j.compstruct.2025.119564https://idr.nitk.ac.in/handle/123456789/19987Revolutionizing advanced sandwich structures, this study delves into the non-linear thermal stability behavior and free vibration characteristics of auxetic aluminum re-entrant core sandwich beams enhanced with graphene origami (GOri) metamaterial facings, subjected to spatially varying thermal environment. The sandwich beams are modeled as layered structures incorporating complex geometric non-linearities, using a higher-order shear deformation framework and non-linear strain–displacement kinematics based on von Kármán assumptions. The governing equations of motion are addressed through the Ritz formulation, enabling an in-depth investigation of how variations in graphene origami layout, concentration, and fold geometry within the face sheets influence the structural performance. Additionally, the influence of various core Poisson's ratio configurations-negative (NPR), zero (ZPR), and positive (PPR)-along with the effects of core angle and thickness ratio, are systematically explored. The results highlight that core topology critically influences post-buckling resistance and non-linear vibrational characteristics. Furthermore, the integration of graphene origami significantly enhances stiffness and structural stability, demonstrating its potential for next-generation aerospace, automotive, and high-performance engineering applications. To the best of the authors’ knowledge, this is the first study to explore the coupled effects of auxetic re-entrant aluminum cores and graphene origami-enhanced facings on the non-linear thermal and dynamic behavior of sandwich beams. © 2025 Elsevier LtdAluminumBucklingBuckling behaviorFacingsMetamaterialsPoisson ratioSandwich structuresShear flowStructural analysisThermodynamic stabilityVibration analysisAuxetic metamaterialAuxeticsGraphene origamiGraphenesLinear vibration analysisNegative Poisson ratioNon-linear vibrationsRe-entrant auxetic core sandwich beamRitz methodsSandwich beamsThermal post-bucklingThermal post-buckling and non-linear vibration analyzeEquations of motion