Free Vibration Analysis of Carbon Nanotube Grid Composite Cylindrical Shell with First-Order Shear Deformation Theory

In this paper, the free vibrations of a composite cylindrical grid shell reinforced with carbon nanotubes are investigated. Equilibrium equations are derived based on first-order shear deformation theory. The orientation of carbon nanotubes is assumed to be uniaxial in the direction of the assumed thickness and the elastic modulus of the polymer composite reinforced with carbon nanotubes is calculated using the Rule of mixture. In order to achieve the stiffness parameter equivalent to the shell of grid cylinders, Smeared method has been used to suppress the effect of ribs. Abaqus software and valid references have been used to validate the obtained results. According to the results, the presence of peripheral ribs in the structure increases the frequency and reduces the radial displacement. Also, the thickness and angles of the ribs are important in improving the frequency and the presence of carbon nanotubes plays an important role in strengthening the structure and Increases the frequency and decreases the radial displacement due to the applied load.