石墨烯增强功能梯度多孔梁材料不确定性对热机械过屈曲行为的影响  

Influence of material uncertainties on thermo-mechanical postbuckling behaviour of graphene reinforced functionally graded porous beams

作　　者：Fahed Mohd Mohammad Talha 

机构地区：[1]Computational Design Lab,School of Mechanical and Materials Engineering,Indian Institute of Technology Mandi,Mandi,175075,India

出　　处：《Acta Mechanica Sinica》2023年第4期21-43,共23页力学学报（英文版）

摘　　要：本文旨在研究石墨烯片增强功能梯度多孔梁材料不确定性对在热环境下的过屈曲行为的影响.通过采用随机有限元方法,已经完成了全面的确定性和随机性研究.考虑了温度依赖性(TD)和温度无关性(TID)的材料特性.使用Halpin-Tsai微力学模型估计了杨氏模量等均质化有效材料性质,通过Voigt混合法则估计了密度和热膨胀系数.假设均质化的材料特性沿厚度方向以功能渐变的方式变化.所开发的公式基于高阶剪切变形理论,结合冯-卡门型几何非线性进行过屈曲分析.开发C^(0)有限元模型求解非线性控制方程组,使用直接迭代过程进行数值求解.所开发方法的收敛和验证研究也通过独立的蒙特卡罗模拟进行,以确保方法的准确性.分别讨论了材料设计参数如孔隙率含量、纳米填料量和材料特性(即杨氏模量、金属基体密度和纳米填料)的低变异性(随机性)等材料不确定性对FGGPLRC多孔梁热机械过屈曲行为的影响.结果表明,材料性能的不确定性会显著影响FG-GPLRC多孔梁的过屈曲响应.This paper aims to investigate the influence of material uncertainties on the postbuckling behaviour of functionally graded porous beams reinforced with graphene platelets when subjected to a thermal environment.A comprehensive deterministic,as well as stochastic study,has been done by employing the stochastic finite element methodology.The temperature-dependent(TD)and temperature-independent(TID)material properties have been considered.The homogenized effective material properties such as Young’s modulus are estimated by using the Halpin-Tsai micromechanics model and the density,and thermal expansion coefficient by Voigt’s rule of mixture.The homogenized material properties are assumed to be varying along the thickness direction in a functionally graded manner.The developed formulation is based on higher-order shear deformation theory in conjunction with Von-Kármán type geometric non-linearity for the postbuckling analysis.A C^(0) finite element model is developed to solve the system of non-linear governing equations,which are solved numerically using the direct iterative procedure.The convergence and validation study of the developed formulation has also been performed with an independent Monte Carlo simulation to ensure the accuracy of the formulation.The influence of material uncertainty on the thermo-mechanical postbuckling behavior of FG-GPLRC porous beams has been discussed for low variability(randomness)in material design parameters such as porosity content,amount of nanofillers,and material properties(i.e.,Young’s modulus,density of metal matrix,and nanofillers)respectively.It was revealed that uncertainties in material properties can significantly affect the postbuckling response of FG-GPLRC porous beams.

关 键 词：杨氏模量 功能梯度 蒙特卡罗模拟 纳米填料 温度依赖性 热膨胀系数 材料特性 直接迭代 

分 类 号：TB33[一般工业技术—材料科学与工程]