Nonlocal strain gradient shell model for axial buckling and postbuckling analysis of magneto-electro-elastic composite nanoshells
Nonlocal strain gradient shell model for axial buckling and postbuckling analysis of magneto-electro-elastic composite nanoshells
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DOI：
10.1016/j.compositesb.2017.09.004
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发表时间：
2018
影响因子：
13.1
通讯作者：
S. Sahmani;M. M. Aghdam-M.
中科院分区：
文献类型：
--
作者：
S. Sahmani;M. M. Aghdam-M.
本文研究了同时考虑硬化刚度和软化刚度尺寸效应的磁电弹性复合纳米圆柱壳的非线性屈曲和后屈曲特性。为了实现这一目的，非局部应变梯度弹性理论被应用到经典壳理论。通过虚功原理，建立了包含轴向压缩载荷、外磁势和外电势耦合项的尺寸相关控制微分方程。基于壳体屈曲的边界层理论，考虑了屈曲前的非线性变形和屈曲后的大挠度。最后，采用改进的微扰技术，得到了不同表面电场和磁场电压下磁电弹纳米壳非局部应变梯度稳定性曲线的解析表达式.结果表明，正电势和负磁势会增加轴向加载磁电弹复合纳米壳的非线性失稳行为的非局域性和应变梯度尺寸依赖性，而负电势和正磁势则起相反的作用.
The present study deals with the size-dependent nonlinear buckling and postbuckling characteristics of magneto-electro-elastic cylindrical composite nanoshells incorporating simultaneously the both of hardening-stiffness and softening-stiffness size effects. To accomplish this purpose, the nonlocal strain gradient elasticity theory is applied to the classical shell theory. Via the virtual work's principle, the size-dependent governing differential equations are constructed including the coupling terms between the axial mechanical compressive load, external magnetic potential and external electrical potential. The nonlinear prebuckling deformations and the large postbuckling deflections are taken into consideration based upon the boundary layer theory of shell buckling. Finally, an improved perturbation technique is employed to achieve explicit analytical expressions for nonlocal strain gradient stability curves of magneto-electro-elastic nanoshells under various surface electric and magnetic voltages. It is seen that a positive electric potential and a negative magnetic potential cause to increase both of the nonlocality and strain gradient size dependencies in the nonlinear instability behavior of axially loaded magneto-electro-elastic composite nanoshells, while a negative electric potential and a positive magnetic potential play an opposite role.