Eshraghi Iman, Jalali Seyed K, Pugno Nicola Maria
School of Mechanical Engineering, University of Tehran, Tehran 1193653471, Iran.
Department of Mechanical Engineering, Kermanshah University of Technology, Kermanshah 6715685438, Iran.
Materials (Basel). 2016 Sep 21;9(9):786. doi: 10.3390/ma9090786.
Imperfection sensitivity of large amplitude vibration of curved single-walled carbon nanotubes (SWCNTs) is considered in this study. The SWCNT is modeled as a Timoshenko nano-beam and its curved shape is included as an initial geometric imperfection term in the displacement field. Geometric nonlinearities of von Kármán type and nonlocal elasticity theory of Eringen are employed to derive governing equations of motion. Spatial discretization of governing equations and associated boundary conditions is performed using differential quadrature (DQ) method and the corresponding nonlinear eigenvalue problem is iteratively solved. Effects of amplitude and location of the geometric imperfection, and the nonlocal small-scale parameter on the nonlinear frequency for various boundary conditions are investigated. The results show that the geometric imperfection and non-locality play a significant role in the nonlinear vibration characteristics of curved SWCNTs.
本研究考虑了弯曲单壁碳纳米管(SWCNT)大幅振动的缺陷敏感性。将SWCNT建模为铁木辛柯纳米梁,并将其弯曲形状作为位移场中的初始几何缺陷项包含在内。采用冯·卡门型几何非线性和厄林根非局部弹性理论推导运动控制方程。使用微分求积法(DQ)对控制方程和相关边界条件进行空间离散,并迭代求解相应的非线性特征值问题。研究了几何缺陷的幅度和位置以及非局部小尺度参数对各种边界条件下非线性频率的影响。结果表明,几何缺陷和非局部性在弯曲SWCNT的非线性振动特性中起着重要作用。