Study on size-dependent bending behavior of axially functionally graded microbeams via nonlocal strain gradient theory  

基于非局部应变梯度理论的轴向功能梯度微梁尺度相关弯曲行为研究（英文）

作　　者：Kang Zetian Wang Zhiyong Zhou Bo Xue Shifeng 康泽天;王志勇;周博;薛世峰(中国石油大学(华东)储运与建筑工程学院)

机构地区：[1]College of Pipeline and Civil Engineering,China University of Petroleum(East China),Qingdao 266580,China

出　　处：《Journal of Southeast University(English Edition)》2019年第4期453-463,共11页东南大学学报（英文版）

基　　金：The National Key Research and Development Program of China(No.2017YFC0307604);the Talent Foundation of China University of Petroleum(No.Y1215042)

摘　　要：Based on the nonlocal strain gradient theory(NSGT),the static bending behaviors of an axially functionally graded(AFG)Bernoulli-Euler microbeam subjected to concentrated and distributed loads are studied.The material property of the AFG microbeam changes continuously along the longitudinal direction.On the basis of the minimum potential energy principle,the equations of motion and associated classical and non-classical boundary conditions are derived.Then,Galerkin’s weighted residual method in conjunction with the normalization technique are utilized to solve the governing differential equations.The transverse deformations of the AFG microbeam suffering the sinusoidal distributed load within the framework of NSGT,nonlocal elasticity theory(NET),strain gradient theory(SGT)and classical elasticity theory(CET)are compared.It is observed that the bending flexibility of the microbeam decreases with the increase in the ratio of the material length scale parameter to the beam height.However,the bending flexibility increases with the increase in the material nonlocal parameter.The functionally graded parameter plays an important role in controlling the transverse deformation.This study provides a theoretical basis and a technical reference for the design and analysis of AFG micro-beams in the related regions.基于非局部应变梯度理论,研究了轴向功能梯度Bernoulli-Euler微梁在集中载荷和分布载荷作用下的弯曲行为.轴向功能梯度微梁的材料参数沿轴向连续变化.基于最小势能原理,推导了微梁的运动方程以及相应的经典和非经典边界条件,并利用Galerkin加权余量法和归一化技术对控制微分方程进行了求解.在非局部应变梯度理论、非局部弹性理论、应变梯度理论和经典弹性理论的框架下,对受正弦分布荷载作用的轴向功能梯度微梁的横向变形进行了比较.结果表明,微梁的弯曲柔度随材料长度尺度参数与梁高比值的增大而减小,但随材料非局部参数的增大而增大,功能梯度参数对控制微梁挠度具有重要作用.该工作可为相关领域内轴向功能梯度微梁的设计和分析提供理论依据和技术参考.

关 键 词：axially functionally graded microbeam nonlocal strain gradient theory bending Galerkin method normalization method 

分 类 号：O341[理学—固体力学]