Thermal Post-Buckling Strength Prediction and Improvement of Shape Memory Alloy Bonded Carbon Nanotube-Reinforced Shallow Shell Panel: A Nonlinear Finite Element Micromechanical Approach

This article reported first-time the post-buckling temperature load parameter values of nanotube-reinforced polymeric composite panel and their improvement by introducing the functional material (shape memory alloy, SMA) fiber. The temperature load values of nanotube composite and SMA activation are modeled using the single-layer type higher-order kinematic model in association with isoparametric finite element technique. To ensure the effective properties of SMA bonded nanotube composite under the elevated temperature, a hybrid micromechanical material modeling approach is adopted (Mori-Tanaka scheme and rule of mixture). The present structural geometry distortion under elevated temperature is modeled through the nonlinear strain kinematics (Green-Lagrange), whereas the strain reversal achieved with the help of marching technique (inclusion of material nonlinearity). Owing to the importance of geometrical distortion of the polymeric structure, the current model includes all of the nonlinear strain terms to accomplish the exact deformation. Further, to compute the post-buckling responses, the governing nonlinear eigenvalue equations are derived by Hamilton's principle. The numerical solution accuracy is verified with adequate confirmation of model consistency. The material model applicability for different structural configurations including important individual/combined parameter tested through a series of examples. Moreover, the final understanding relevant to the post-buckling characteristics of the polymeric structure and SMA influences is highlighted in details considering the prestrain, recovery stress, and their volume fractions.