The size-dependent elastic properties of nanofilms with surface effects

2020-02-23 23:46:22

surface elastic constants dependent nanofilm

责任者: Jian-Gang Guo;Ya-Pu Zhao 单位: State Key Lab. of Nonlinear Mech., Chinese Acad. of Sci., Beijing, China 来源出处: Journal of Applied Physics(J. Appl. Phys. (USA)),2005/10/01,98(7):74306-1 摘要: Size-dependent elastic constants are investigated theoretically with reference to a nanoscale single-crystal thin film. A three-dimensional (3D) model is presented with the relaxation on the surface of the nanofilm taken into consideration. The constitutive relation of the 3D model is derived by using the energy approach, and analytical expressions for the four nonzero elastic constants of the nanofilm are obtained. The size effects of the four elastic constants are then discussed, and the dependence of these elastic constants on the surface relaxation and the ambiguity in the definition of the thickness of the nanofilm are also analyzed. In addition, the elastic moduli of the nanofilm in two kinds of plane problem are obtained and discussed in the case of a special boundary condition 关键词: elastic constants;elastic moduli;nanostructured materials;thin films;size-dependent elastic constants;nanoscale single-crystal thin film;surface effects;three-dimensional model;surface relaxation;elastic moduli