▎ 摘　　要

In this paper, the structural damping behavior of axisymmetric nanocomposite cylinders enhanced with randomly oriented graphene nanosheets has been explored by a mesh-free solution. The static responses of such nanocomposite cylinders under internal pressure and exposed to thermal environment are assumed as the initial condition of harmonic vibrations. Using the shape functions of moving least squares (MLS), an axisymmetric mesh-free solution has been developed to approximate the displacement field of the graphene-enhanced nanocomposite (GEN) cylinders. Along the thickness of these cylinders, different nonlinear functionally graded (FG) patterns are considered for the distribution of graphene nanosheets. The mechanical properties of graphene and polymer are considered to vary with temperature, and the overall properties of nanocomposite are calculated using a modified Halpin-Tsai (HS) technique. The effects of thermal environment, graphene content, graphene dispersion, and cylinder dimension on the structural damped harmonic vibrations of axisymmetric GEN cylinders have been examined. The results indicate that the use of graphene nanosheets and their distribution significantly affect the damped harmonic vibrations of axisymmetric polymeric cylinders such that the increase of graphene content results in damped vibrations with higher frequency and shorter stationary time. In addition, thermal environment reduced the frequency of vibrations, but it has an insignificant impact on the stationary time of vibrations.