ABSTRACT

This is the first research on the smart control and frequency analysis of a cylindrical sandwich nanoshell in the framework of the numerical-based generalized differential quadrature method (2D-GDQM). The current sandwich smart nanostructure is made of a honeycomb core and piezoelectric face sheets as sensor and actuator (PFSA). For modeling the size-dependent nanoshell, nonlocal stress-strain gradient theory (NSGT) is presented. Also, this nanostructure is under conveying viscous fluid, and the related force is calculated by the modified formulation of Navier–Stokes. Also, the current structure rotates around its axial direction. The stresses and strains are obtained using the higher-order shear deformation theory (HSDT). The external voltage is applied to the sensor layer, and a Proportional-Derivative (PD) controller is used for sensor output control. Governing equations and boundary conditions of the cylindrical sandwich nanoshell are obtained by implementing Hamilton’s principle. The results show that the geometry of honeycomb core, PD controller, velocity of fluid flow, length to radius ratio (L/R), and applied voltage and have a significant influence on the frequency characteristics of a cylindrical sandwich nanoshell. Another important consequence is that applying the PD controller leads to an increase in the critical velocity of fluid flow in the smart nanostructure.

摘要

这是在基于数值的广义微分正交方法（2D-GDQM）框架下对圆柱形夹心纳米壳的智能控制和频率分析的首次研究。当前的三明治智能纳米结构由蜂窝芯和压电面板作为传感器和执行器（PFSA）制成。为了模拟尺寸相关的纳米壳，提出了非局部应力-应变梯度理论 (NSGT)。此外，该纳米结构正在输送粘性流体，相关力由 Navier-Stokes 的修改公式计算。此外，当前结构围绕其轴向旋转。应力和应变是使用高阶剪切变形理论 (HSDT) 获得的。外部电压施加到传感器层，比例微分 (PD) 控制器用于传感器输出控制。通过实施汉密尔顿原理，获得了圆柱形夹心纳米壳的控制方程和边界条件。结果表明，蜂窝芯的几何形状、PD控制器、流体流速、长径比（L/R ) 和外加电压对圆柱形夹心纳米壳的频率特性有显着影响。另一个重要的结果是应用 PD 控制器导致智能纳米结构中流体流动的临界速度增加。