个人信息Personal Information
性别：男
学科：力学. 航空宇航科学与技术. 材料科学与工程. 机械工程. 冶金工程. 先进制造. 航空工程. 材料工程. 冶金工程. 机械工程. 固体力学
多尺度力学，宏微观力学，梯度结构材料，界面力学，固体本构关系，应变梯度理论，晶体塑性有限元，离散位错动力学，分子动力学，高熵合金，大数据与机器学习，材料基因，极端力学，高性能材料，材料的增强与增韧
2020-06-02 多尺度材料力学研究组与张波博士合作发表的论文 “Coupling effects of surface energy, strain gradient, and inertia gradient on the vibration behavior of small-scale beams”在期刊 International Journal of Mechanical Sciences 上在线发表。
发布时间：2020-06-02
Highlights
•Surface energy-enriched gradient elastic EB, TB, and LBRB models were developed.
•Euler-Lagrange variational formulations for general gradient elastic beams were derived.
•Differential quadrature finite elements were established to solve the general free vibration problems of small-scale beams.
•Three types of size effects can significantly change the vibration frequencies and mode shapes of small-scale beams.
•The introduction of the strain gradient effect may induce a boundary layer for small-scale beams with at least one end clamped.
Abstract
This paper develops three surface energy-enriched gradient elastic beam models, respectively, in the contexts of Euler-Bernoulli, Timoshenko, and Levinson-Brickford-Reddy kinematic hypotheses to investigate the coupling effects of surface energy, strain gradient, and inertia gradient on the vibration behavior of small-scale beams. Modified strain-inertia gradient elasticity theory and Gurtin-Murdoch surface elasticity theory are combined to capture three types of small-scale effects. The equations of motion and consistent boundary conditions are derived by using the Euler-Lagrange variational principle. To analyze the general free vibration problems of three non-classical beam models, we construct the related differential quadrature finite elements according to two kinds of differential quadrature-based geometric mapping schemes. The efficacy of our theoretical models and numerical solution methods is established by comparing the degenerated results with the reported ones. Finally, we apply the newly developed models to investigate the size-dependent behavior of freely vibrating small-scale beams. It is revealed that the coupling effects of three physical factors can result in not only the stiffening or softening characteristic of vibration frequencies but also the significant change in the vibration mode shapes. Besides, the introduction of the strain gradient effect may induce a boundary layer for small-scale beams with at least one end clamped.
Link
https://doi.org/10.1016/j.ijmecsci.2020.105834