Analytical Solution for Thermal Buckling of Functionally Graded Graphene Origami-Enabled Auxetic Metamaterial Cylindrical Shells.

Composite cylindrical shells suffer from thermal buckling in harsh thermal environments, impairing overall structural safety. This study aims to improve the thermal stability of such shells by investigating the thermal buckling behavior of graphene origami metamaterial-reinforced composite cylindrical shells. Four common thickness-wise distribution patterns (UD, FG-X, FG-O, and FG-A) are adopted, and temperature-dependent material properties are taken into account. Based on classical thin-shell theory with geometric nonlinearity, thermal buckling governing equations are derived. Analytical solutions of critical buckling temperature rises are obtained via an iterative procedure for both temperature-dependent and temperature-independent material models. Parametric studies are conducted to explore key influencing factors including reinforcement distribution, filler content, folding degree, tangential edge constraints, and shell geometric parameters. The results reveal that critical buckling temperature is strongly dependent on graphene origami distribution and structural features. Increasing filler content enhances thermal buckling resistance, while folding degree also dominates structural stability. Additionally, tangential constraints and geometric dimensions exert obvious effects. Significant discrepancies exist between two material models, verifying that temperature-dependent material properties are essential for precise thermal buckling analysis of the proposed composite shells.