Size-dependent bistability of an electrostatically actuated arch NEMS based on strain gradient theory
Size-dependent bistability of an electrostatically actuated arch NEMS based on strain gradient theory
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DOI：
10.1088/0022-3727/48/24/245503
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发表时间：
2015-05
期刊：
影响因子：
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通讯作者：
Farid Tajaddodianfar;H. N. Pishkenari;M. Yazdi;E. M. Miandoab
中科院分区：
文献类型：
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作者：
Farid Tajaddodianfar;H. N. Pishkenari;M. Yazdi;E. M. Miandoab
本文研究了在空间分布静电力作用下，双固支纳米浅拱中非线性动力学的尺寸依赖性。我们利用应变梯度理论，结合欧拉-伯努利假设和浅拱形假设，推导出考虑中面拉伸效应的拱形横向运动的非线性偏微分方程组。利用Galerkin投影法建立了集总单自由度模型，并将其用于研究拱形纳米机电系统(NEMS)的非线性跳跃和拉入失稳的尺寸效应。此外，利用应变梯度理论研究了纳米拱形结构的尺寸相关双稳特性和基频特性，发现与经典理论预测的结果不同，纳米结构参数空间中的双稳区域随着结构尺寸的缩小而缩小。此外，我们还表明，双稳所需的最小初始高度随着纳米弓的缩小而增加。
This paper deals with the investigation of the size-dependent nature of nonlinear dynamics, in a doubly clamped shallow nano-arch actuated by spatially distributed electrostatic force. We employ strain gradient theory together with the Euler–Bernoulli and shallow arch assumptions in order to derive the nonlinear partial differential equation governing the transverse motion of the arch with mid-plane stretching effects. Using the Galerkin projection method, we derive the lumped single degree of freedom model which is then used for the study of the size effects on the nonlinear snap-through and pull-in instabilities of the arch nano-electro-mechanical-system (NEMS). Moreover, using strain gradient theory, the size-dependent bistability and fundamental frequencies of the nano-arch are scrutinized, revealing that, despite what is predicted by the classical theory, the bistability region in the parameter space of the nano-structure shrinks as the structure scales down. Also, we show that the minimum initial elevation, required for bistability, increases as the nano-arch scales down.