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.

中文翻译：

---

热环境中轴对称石墨烯增强圆柱体的阻尼谐波振动

在本文中，通过无网格解决方案探索了随机取向的石墨烯纳米片增强的轴对称纳米复合圆柱体的结构阻尼行为。这种纳米复合材料圆柱体在内部压力和暴露于热环境下的静态响应被假定为谐波振动的初始条件。使用移动最小二乘法 (MLS) 的形状函数，已开发出一种轴对称无网格解决方案来近似石墨烯增强纳米复合材料 (GEN) 圆柱体的位移场。沿着这些圆柱体的厚度，石墨烯纳米片的分布考虑了不同的非线性功能梯度 (FG) 模式。石墨烯和聚合物的机械性能被认为随温度变化，并且使用改进的 Halpin-Tsai (HS) 技术计算纳米复合材料的整体性能。已经研究了热环境、石墨烯含量、石墨烯分散和圆柱体尺寸对轴对称 GEN 圆柱体结构阻尼谐波振动的影响。结果表明，石墨烯纳米片的使用及其分布显着影响轴对称聚合物圆柱体的阻尼谐波振动，使得石墨烯含量的增加导致具有更高频率和更短静止时间的阻尼振动。此外，热环境降低了振动频率，但对振动的平稳时间影响不大。轴对称 GEN 圆柱的结构阻尼谐波振动的圆柱尺寸和圆柱尺寸已被检验。结果表明，石墨烯纳米片的使用及其分布显着影响轴对称聚合物圆柱体的阻尼谐波振动，使得石墨烯含量的增加导致具有更高频率和更短静止时间的阻尼振动。此外，热环境降低了振动频率，但对振动的平稳时间影响不大。轴对称 GEN 圆柱的结构阻尼谐波振动的圆柱尺寸和圆柱尺寸已被检验。结果表明，石墨烯纳米片的使用及其分布显着影响轴对称聚合物圆柱体的阻尼谐波振动，使得石墨烯含量的增加导致具有更高频率和更短静止时间的阻尼振动。此外，热环境降低了振动频率，但对振动的平稳时间影响不大。结果表明，石墨烯纳米片的使用及其分布显着影响轴对称聚合物圆柱体的阻尼谐波振动，使得石墨烯含量的增加导致具有更高频率和更短静止时间的阻尼振动。此外，热环境降低了振动频率，但对振动的平稳时间影响不大。结果表明，石墨烯纳米片的使用及其分布显着影响轴对称聚合物圆柱体的阻尼谐波振动，使得石墨烯含量的增加导致具有更高频率和更短静止时间的阻尼振动。此外，热环境降低了振动频率，但对振动的平稳时间影响不大。