Nonlinear three-dimensional stability characteristics of geometrically imperfect nanoshells under axial compression and surface residual stress
IF 6.1
3区 材料科学
Q1 CHEMISTRY, MULTIDISCIPLINARY
引用次数: 6
Abstract
Abstract Through reduction of thickness value in nanostructures, the features of surface elasticity become more prominent due to having a high surface-to-volume ratio. The main aim of this research work was to examine the surface residual stress effect on the three-dimensional nonlinear stability characteristics of geometrically perfect and imperfect cylindrical shells at nanoscale under axial compression. To do so, an unconventional three-dimensional shell model was established via combination of the three-dimensional shell formulations and the Gurtin–Murdoch theory of elasticity. The silicon material is selected as a case study, which is the most utilized material in the design of micro-electromechanically systems. Then, the moving Kriging meshfree approach was applied to take numerically into account the surface free energy effects and the initial geometrical imperfection in the three-dimensional nonlinear stability curves. Accordingly, the considered cylindrical shell domain was discretized via a set of nodes together using the quadratic polynomial type of basis shape functions and an appropriate correlation function. It was found that the surface stress effects lead to an increase the critical axial buckling load of a perfect silicon nanoshell about 82.4 % 82.4 \% for the shell thickness of 2 nm 2{\rm{nm}} , about 32.4 % 32.4 \% for the shell thickness of 5 nm 5{\rm{nm}} , about 15.8 % 15.8 \% for the shell thickness of 10 nm 10{\rm{nm}} , and about 7.5 % 7.5 \% for the shell thickness of 20 nm 20{\rm{nm}} . These enhancements in the value of the critical axial buckling load for a geometrically imperfect silicon nanoshell become about 92.9 % 92.9 \% for the shell thickness of 2 nm 2{\rm{nm}} , about 36.5 % 36.5 \% for the shell thickness of 5 nm 5{\rm{nm}} , about 17.7 % 17.7 \% for the shell thickness of 10 nm 10{\rm{nm}} , and about 8.8 % 8.8 \% for the shell thickness of 20 nm 20{\rm{nm}} .轴向压缩和表面残余应力作用下几何缺陷纳米壳的非线性三维稳定性特征
摘要通过降低纳米结构的厚度值，由于具有高的表面体积比，表面弹性的特征变得更加突出。本研究工作的主要目的是考察表面残余应力对几何完美和非完美圆柱壳在轴向压缩下纳米尺度三维非线性稳定特性的影响。为此，通过结合三维壳体公式和Gurtin–Murdoch弹性理论，建立了一个非常规的三维壳体模型。选择硅材料作为案例研究，它是微机电系统设计中使用最多的材料。然后，应用移动Kriging无网格方法对三维非线性稳定曲线中的表面自由能效应和初始几何缺陷进行了数值计算。因此，通过一组节点，使用二次多项式类型的基形状函数和适当的相关函数，对所考虑的圆柱壳域进行离散化。研究发现，表面应力效应导致完美硅纳米壳的临界轴向屈曲载荷增加，对于2 nm 2｛\rm｛nm｝的壳厚度增加约82.4%82.4%，对于5 nm 5｛\rm｛nm｛｝的壳体厚度增加约32.4%32.4%，对于10 nm 10｛\rm｛nm}的壳体厚度提高约15.8%15.8%，对于20 nm 20｛\rms｛nm的壳体厚度则增加约7.5%7.5%。几何上不完美的硅纳米壳的临界轴向屈曲载荷值的这些增强对于2 nm 2｛\rm｛nm｝的壳厚度为约92.9%92.9%，对于5 nm 5｛\rm｛nm｛｝的壳体厚度为约36.5%36.5%，对于10 nm 10｛\rm｛nm}的壳体厚度约17.7%17.7%，并且对于20 nm 20｛\rms｛nm｝的壳层厚度为约8.8%8.8%。
本文章由计算机程序翻译，如有差异，请以英文原文为准。
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来源期刊
Nanotechnology Reviews
CHEMISTRY, MULTIDISCIPLINARY-NANOSCIENCE & NANOTECHNOLOGY
CiteScore
11.40
自引率
13.50%
发文量
137
审稿时长
7 weeks
期刊介绍：
The bimonthly journal Nanotechnology Reviews provides a platform for scientists and engineers of all involved disciplines to exchange important recent research on fundamental as well as applied aspects. While expert reviews provide a state of the art assessment on a specific topic, research highlight contributions present most recent and novel findings.
In addition to technical contributions, Nanotechnology Reviews publishes articles on implications of nanotechnology for society, environment, education, intellectual property, industry, and politics.
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