Forced Vibration Analysis of Functionally Graded Cylinders Reinforced by Wavy Carbon Nanotube Using a Mesh-Free Method

In this paper, forced vibration analysis of functionally graded (FG) nanocomposite cylinders reinforced by wavy carbon nanotubes (CNTs) subjected to time depended internal pressure is investigated by a mesh-free method. In the mesh-free analysis, moving least squares (MLSs) shape functions are used for approximation of displacement field in the weak form of motion equation. The applied nanocomposite is a mixture of wavy single-walled carbon nanotubes (SWCNTs) reinforced in isotropic matrix material. Material properties are estimated by a micro mechanical model and new extended rule of mixture. Micromechanics equations cannot capture the scale difference between the nano and micro levels. In order to overcome this problem, some efficiency parameters are defined. In this simulation, an axisymmetric model is used and three linear types of FG distributions of wavy CNTs and a uniform distribution are considered along the radial direction of cylinder. The results of mesh-free method and mechanical properties are verified by finite element method (FEM), experimental and theoretical results. Effects of the distribution kind, aspect ratio, waviness and volume fraction of CNT are investigated on forced vibration analysis of the FG nanocomposite cylinders. It's observed that CNT waviness and volume fraction have a significant effect on the vibrational behavior of the CNT-reinforced cylinders.