Resonance in functionally graded nanocomposite cylinders reinforced by wavy carbon nanotube

Abstract

In this article, free vibration and resonance of finite length functionally graded (FG) nanocomposite cylinders are investigated by a mesh-free method. These cylinders are reinforced by wavy single-walled carbon nanotubes (SWCNTs) and subjected to a periodic internal pressure. Three linear types of FG distributions and a uniform distribution of wavy carbon nanotubes (CNTs) are considered along the radial direction of axisymmetric cylinder. The mechanical properties are simulated using a micromechanical model in volume fraction form. In the mesh-free analysis, moving least squares shape functions are used for approximation of displacement field in the weak form of motion equation and the transformation method is used for imposition of essential boundary conditions. Effects of geometric dimensions, boundary conditions and also, waviness index, aspect ratio, volume fraction, and distribution pattern of CNTs are investigated on the natural frequencies and resonance behaviors of FG carbon nanotube reinforced composite (CNTRC) cylinders. It is observed that CNT waviness has a significant effect on the vibrational behavior of the CNTRC cylinders.

Stress distributions in nanocomposite sandwich cylinders reinforced by aggregated carbon nanotube

“…An excellent agreement between the FEM results and exact solution can be seen which proves the high accuracy of the developed FEM. Moreover, the accuracy of the developed FEM was also verified for stress distribution in FGM cylinders by comparison with analytical and numerical methods in .…”

“…The weak form of equilibrium equation for the sandwich cylinder subjected to mechanical loads can be expressed : where σ , ε , u , and F are the vectors of stress, strain, displacement and surface traction, respectively. Γ is a part of boundary of domainΩ on which traction F is applied.…”

“…Safari et al developed an axisymmetric FE model to study vibration and damping behavior of hallow FG‐CNTRC cylinders filled by magneto‐rheological oil. Also, a mesh‐free method based on MLS shape functions and transformation method was utilized for static, free vibration, and dynamic behavior axisymmetric cylinders reinforced by FG distribution of wavy CNTs .…”

“…Using a multiscale approach, the free vibration behavior of laminated three‐phase nanocomposite shells and plates reinforced with agglomeration of CNTs and fibers were presented by Tornabene et al . Moradi‐Dastjerdi et al also investigated the effect of CNT orientation and aggregation on the static behavior axisymmetric cylinders under internal pressures.…”

“…One of the most important concerns in the use of CNTs to reinforce a polymeric matrix is the formation of CNT agglomerations, especially in high values of CNTs volume fractions [40]. The main reasons of formation of CNT agglomeration are CNT's low bending rigidity and high aspect ratio (usually >1,000).…”