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| Strain burst model and intermittent plastic flow of single crystal nanopillar under displacement loading mode |
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Abstract The micro-compression tests revealed significant strain bursts during plastic deformation of single crystal nanopillar, showing special intermittent plastic flow behaviors. In this paper, a three-stage formulation of the strain burst phenomenon is presented according to the experimental observations of single-crystal Au pillars with a diameter of several hundred nanometers under displacement loading mode. A continuum mechanics model with the second-order work parameter is then developed to describe the intermittent plastic flow within crystal plasticity framework, and their finite element implementation is realized. By comparing to the experimental results, the newly proposed theoretical model is verified to be able to describe the strain bursts and plastic flow of face-centered cubic single crystal under displacement loading mode, with a reasonable accuracy in predicting the plastic deformation behavior of nanopillars. In addition, the second-order work criterion is effective in judging the occurrence of strain bursts event under the condition of displacement loading. Using this model, the randomness, size dependency and rate sensitivity of strain bursts during the plastic deformation of nanopillars are further investigated in detail.
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Received: 12 January 2018
Published: 28 October 2018
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2018, Vol. 39 
