Thermal buckling strength of smart nanotube-reinforced doubly curved hybrid composite panels

The eigenvalue buckling responses of smart carbon nanotube-reinforced hybrid composite shell structure are analyzed under the influence of uniform thermal loading using a multiscale material model. The hybrid nanotube shell structural model is formulated mathematically via a cubic-order shear deformation theory introducing the material nonlinearity due to the shape memory alloy fiber. Additionally, the nanotube-reinforced composite properties are evaluated via two material modeling techniques (Mori-Tanaka technique and rule of mixture) considering the variable scale effect due to hybridization. The final form of the eigenvalue buckling equation is obtained via Hamilton's principle (a dynamic version of the variational technique) including the temperature-dependent properties and thermal loading. The structural model is derived considering the distortion due to the in-plane thermal loading via the generic type of strain kinematics, i.e. Green-Lagrange nonlinearity. The thermal load values are predicted further by solving the derived eigenvalue equation using a nine-node isoparametric quadrilateral element from the finite element technique. The novelty of this research is that first time the shape memory alloy type functional material has been introduced with nanotube-reinforced composite shell structure to highlight the shape memory effect on the improvement of thermal buckling temperature. The derived numerical model is engaged further to solve varieties of examples for comprehensive testing (accuracy and reliability). Finally, a series of parametric analyzes has been performed for different design considerations associated with geometry as well as the material to show the model applicability.