Publicou 6 edições por ano
ISSN Imprimir: 1543-1649
ISSN On-line: 1940-4352
Indexed in
A Micropillar Compression Simulation by a Multiscale Plastic Model Based on 3-D Discrete Dislocation Dynamics
RESUMO
In this article, a microcompression test for the Cu single-crystal micropillar containing an initial dislocation network is simulated by a multiscale computational model. This model combines a 3-D discrete dislocation dynamics (DDD) approach and a finite element method (FEM). The DDD code calculates the plastic strain induced by the slip of dislocation lines in a finite single crystal, which serves as a substitute for the constitutive relationship used in the conventional continuum mechanics. On the other hand, the displacement and stress field in crystal are calculated by FEM. In our simulations, the compression stress-strain curve ofthe micropillars can be divided into three distinct stages: a linear hardening stage, a normal plastic strain hardening stage, and a dislocation starvation hardening stage, accompanying a rather high stress level. The simulation results show that this atypical mechanical behavior is related with the effective "spiral dislocation sources" operation at the second stage and the dislocations escape from the free surfaces at the third stage. At last, the micropillar is almost dislocation-free, as observed in recent experiments.
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Zhao Xue-Chuan , Liu Xiao-Ming , Gao Yuan , Zhuang Zhuo , Molecular dynamical investigation on plastic behavior of Cu(100) twist-grain boundary under shear load, Acta Physica Sinica, 59, 9, 2010. Crossref