• 论文 •

### 基于分子动力学模拟的金属构件的弹-塑性分解方法

1. LSEC, ICMSEC, 中国科学院数学与系统科学研究院, 北京 100190;中国科学院大学数学科学学院, 北京 100049
• 收稿日期:2020-03-10 出版日期:2020-08-15 发布日期:2020-08-15
• 基金资助:

国家自然科学基金重点项目（51739007）资助.

Cui Junzhi, Yu Yifan. ELASTIC-PLASTIC DECOMPOSITION METHOD OF METALLIC STRUCTURE BASED ON MOLECULE DYNAMICS SIMULATION[J]. Mathematica Numerica Sinica, 2020, 42(3): 279-297.

### ELASTIC-PLASTIC DECOMPOSITION METHOD OF METALLIC STRUCTURE BASED ON MOLECULE DYNAMICS SIMULATION

Cui Junzhi, Yu Yifan

1. LSEC, ICMSEC, Academy of Mathematics and Systems Science, CAS, Beijing 100190, China;School of Mathematical Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
• Received:2020-03-10 Online:2020-08-15 Published:2020-08-15

In this paper a new elastic-plastic strain decomposition method is proposed based on Molecule Dynamics(MD) simulation for metallic structures. First the motion traces of atoms are decomposed into structural deformation component and thermal vibration, then the computational method and approximate formulae on the structural deformation are given. To the current configuration of the structure the continuous deformation functions are constructed based on the composition pattern of BCC|FCC cells and tetrahedral elements supported by 4-atoms, and the algorithm of deformation gradient is shown. And by using the atomic-continuum coupled model the calculation formulae of the stress fields and elasticity tensor are developed. And then, the micro-defect forms generated by overlarge loading inside materials are analyzed, and classified into dislocations, stacking faults, twin boundaries, grain boundaries and vacancies et al. The constrained equations of rigid body motion satisfied for the stacking faults and twin boundaries during the elastic unloading process are derived, then the elastic unloading algorithm of current configuration is created by making use of minimum potential energy principle. Further, the entire elastic-plastic strain decomposition algorithm based on MD simulation is proposed. Finally, the numerical results for the tension of single crystal Cu nanowire are shown. It shows that the elastic-plastic strain decomposition method in this paper is reasonable.
The elastic-plastic decomposition method based on MD simulation presented above can be applied into the multi-scales analysis coupled with multiple models for mechanic behaviors of materials and their structures.

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