Keating改良模型的硅纳米梁动态特性

提出一种用于分析硅纳米梁动态特性的改良型半连续体模型,对比传统的连续体理论,这种新模型使用了Keating势,并考虑了纳米梁在宽厚两个维度的分立特性。依据Sun-Zhang模型思想和能量守恒定律,建立了改良型Keating模型,并进行了双端固支梁的基频计算。在这个过程中,对一些表面效应也进行系统分析。结果表明,该改良模型一方面在纳米尺度下与Material StudioTM软件仿真结果较为符合,另一方面也能在微观尺度下较好的接近连续体模型的计算数据。同时,该模型还反映了基频随纳米梁宽度变化的特性,这也符合一些实际实验。

Modified Keating model for dynamic characteristics of silicon nanobeam

A new semicontinuum model is presented to analyze the dynamic characteristics of silicon nanobeam in this paper. Compared with tradition continuum theory, the new model utilizes the Keating potential and accounts for the discrete nature in the thickness and width directions of the nanobeam. Referring to Sun-Zhang model and using energy conservation theory, the modified Keating model is built. Then the fundamental frequencies of nanoscale clamped-clamped silicon beam are calculated, and the surface effect is considered into the calculation. It is shown that the results based on the new model coincide well either with the results using Material StudioTM software in nano-size or with those based on the continuum model in micro-size. Meanwhile, the model can reflect the fundamental frequency changing with the width, it also accords with the actual experiment.