Abstract

Due to wide-ranging applications of piezoelectric nanostructures as the next generation of smart devices, this article analyzes size-dependent buckling and free vibration performance of fluid-conveying functionally graded-graphene nanoplatelets reinforced composite (FG-GPLRC) porous cylindrical nanoshell embedded in piezoelectric layer and subjected to the temperature gradient and a uniform electrical field based on modified couple stress theory incorporated into first-order shear deformation theory. Classical continuum theories are unable to capture the size effects on small-scale structures; thus, it is required to employ a nonclassical theory. To accomplish this purpose, modified couple stress theory is utilized to present a size-dependent shell model in which its displacement field is formulated by first-order shear deformation theory. The mechanical properties of the GPLRC layer are estimated based on modified Halpin-Tsai micromechanics and the rule of mixtures. Hamilton’s principle is employed to develop governing equations of motion and boundary conditions. Eventually, an analytical solution is prepared based on the Navier method to obtain critical voltage, critical buckling load, and natural frequency in the case of simply supported nanoshell, whereas, for other boundary conditions, the differential quadrature method is employed to solve the problem semi-analytically. The numerical illustration reveals that graphene reinforcement and porosity affect free vibration and buckling behavior of the nanoshell significantly. Moreover, it is concluded that the effect of fluid flow on vibration behavior nanoshell is more noticeable.

摘要

由于压电纳米结构作为下一代智能设备的广泛应用，本文分析了嵌入压电中的流体输送功能梯度石墨烯纳米片增强复合材料（FG-GPLRC）多孔圆柱形纳米壳的尺寸依赖性屈曲和自由振动性能。层并经受温度梯度和基于修正耦合应力理论的均匀电场，该理论并入一阶剪切变形理论。经典连续统理论无法捕捉到小尺度结构的尺寸效应；因此，需要采用非经典理论。为了实现这一目的，修正耦合应力理论被用来提出一个尺寸相关的壳模型，其中其位移场由一阶剪切变形理论制定。GPLRC 层的机械性能基于改进的 Halpin-Tsai 微力学和混合规则进行估计。汉密尔顿原理用于开发运动控制方程和边界条件。最后，基于Navier方法得到解析解，得到简支纳米壳情况下的临界电压、临界屈曲载荷和固有频率，而对于其他边界条件，采用微分求积法求解半-分析地。数值说明表明，石墨烯增强和孔隙率显着影响纳米壳的自由振动和屈曲行为。此外，得出的结论是流体流动对纳米壳振动行为的影响更为显着。