Nonlinear vibration and instability of fluid-conveying DWBNNT embedded in a visco-Pasternak medium using modified couple stress theory
Nonlinear vibration and instability of fluid-conveying DWBNNT embedded in a visco-Pasternak medium using modified couple stress theory
复制标题
DOI：
10.1007/s12206-013-0709-3
复制
发表时间：
2013-09
影响因子：
1.6
通讯作者：
A. G. Arani;M. Bagheri;R. Kolahchi;Z. K. Maraghi
中科院分区：
文献类型：
--
作者：
A. G. Arani;M. Bagheri;R. Kolahchi;Z. K. Maraghi
研究了双壁氮化硼纳米管（DWBNNTs）在粘弹性介质中的非线性自由振动和不稳定性。利用Timoshenko梁理论考虑了横向剪切变形和转动惯量的影响。采用修正的耦合应力理论，考虑材料长度尺度参数对梁模型进行尺寸效应分析。非线性效应由Von Kármán型几何非线性来考虑。采用机电耦合和电荷方程来考虑压电效应。将周围粘弹性介质描述为以弹簧和阻尼器为特征的线性粘-帕斯捷尔纳克基础模型。利用哈密顿原理推导了控制方程和边界条件。采用微分积分法（DQM）对非线性高阶控制方程进行离散化，然后采用直接迭代法对其进行求解，得到具有钳位-钳位（C-C）边界条件的输液dwbnnt的非线性振动频率和临界流体速度。通过详细的参数化研究，阐明了周围粘弹性介质的小尺度系数、弹簧常数和阻尼常数以及流体速度对dwbnnt非线性自由振动、不稳定性和电势分布的影响。本研究对纳米器件的设计和智能控制具有一定的指导意义。
Nonlinear free vibration and instability of fluid-conveying double-walled boron nitride nanotubes (DWBNNTs) embedded in viscoelastic medium are studied in this paper. The effects of the transverse shear deformation and rotary inertia are considered by utilizing the Timoshenko beam theory. The size effect is applied by the modified couple stress theory and considering a material length scale parameter for beam model. The nonlinear effect is considered by the Von Kármán type geometric nonlinearity. The electromechanical coupling and charge equation are employed to consider the piezoelectric effect. The surrounding viscoelastic medium is described as the linear visco-Pasternak foundation model characterized by the spring and damper. Hamilton’s principle is used to derive the governing equations and boundary conditions. The differential quadrature method (DQM) is employed to discretize the nonlinear higher-order governing equations, which are then solved by a direct iterative method to obtain the nonlinear vibration frequency and critical fluid velocity of fluid-conveying DWBNNTs with clamped-clamped (C-C) boundary conditions. A detailed parametric study is conducted to elucidate the influences of the small scale coefficient, spring and damping constants of surrounding viscoelastic medium and fluid velocity on the nonlinear free vibration, instability and electric potential distribution of DWBNNTs. This study might be useful for the design and smart control of nano devices.