Lattice dynamical finite-element method
Lattice dynamical finite-element method
复制标题
DOI：
10.1016/j.actamat.2009.09.029
复制
发表时间：
2010
期刊：
影响因子：
9.4
通讯作者：
Xiaohui Liu;J. Gu;Yao Shen;Ju Li;Changfeng Chen
中科院分区：
文献类型：
--
作者：
Xiaohui Liu;J. Gu;Yao Shen;Ju Li;Changfeng Chen
提出了一种用于应力复杂晶体多尺度分析的点阵动态有限元方法。原子间势被嵌入到超弹性框架内的本构关系中，并且两个基于能量的晶格不稳定性准则，Λ准则和软声子准则，被纳入LDFEM以捕获完美晶体中的应力驱动不稳定性。采用LDFEM和分子动力学方法对B2-NiAl的单轴载荷和二维纳米压痕进行了模拟。两种方法模拟的力学响应吻合较好，验证了所提方法的有效性。这两个准则的结合可以为预测在零或低温载荷下复杂晶体的晶格不稳定性提供一个强有力的工具。
A lattice dynamical finite-element method (LDFEM) is proposed for multiscale analysis of stressed complex crystals. Interatomic potential is embedded into the constitutive relation within the hyperelasticity framework, and two energy-based lattice instability criteria, the Λ criterion and the soft phonon criterion, are incorporated into LDFEM for capturing stress-driven instabilities in a perfect crystal. The simulations of uniaxial loadings and a two-dimensional nanoindentation of B2-NiAl are performed using both LDFEM and molecular dynamics (MD). The good agreement of the simulated mechanical responses between the two methods validates the proposed method. Combination of the two criteria can provide a powerful tool for predicting lattice instabilities in complex crystals under load at zero or low temperatures.