A stochastic finite element simulation of strain burst in single crystalline micropillars

作者：Zhang Xu; Shang Fu Lin^*

来源：Transactions of Beijing Institute of Technology, 2014, 34: 21-24.

• Continuum model
• Crystal deformation
• Crystal plasticity
• Micro compressions
• Single-crystalline
• Stochastic finite element method
• Stochastic finite elements
• Theoretical modeling

Microcompression tests revealed that a sequence of strain bursts occurred during plastic deformation of single crystal micropillars, leading to obvious intermittent plastic flow behaviors. A stochastic finite element method was presented within crystal plasticity framework to describe the intermittent characteristics of crystal deformation under the hybrid loading mode (HLM) for both micron-sized pillars and bulk crystal. The theoretical model proposed recently was investigated by comparing the simulation results to the experimental observations and the conventional finite element methods using classic continuum models of plasticity. The results show that the new model could well capture the occurrence of the strain burst and describe a smooth macroscopic curve in the compression tests of macro-samples. In addition, as the diameters of micropillar decrease to tens of micrometers, the model could also reproduce the experimentally observed micropillars' intermittent plastic flow behaviors; the plastic flow of the micropillars proceeds through a sequence of intermittent burst slips.

• 出版日期2014