Stress and strain fluctuations in plastic deformation of crystals with disordered microstructure
Stress and strain fluctuations in plastic deformation of crystals with disordered microstructure
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DOI：
10.1088/1742-5468/2015/08/p08009
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发表时间：
2015-08
期刊：
影响因子：
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通讯作者：
O. Kapetanou;D. Weygand;M. Zaiser
中科院分区：
文献类型：
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作者：
O. Kapetanou;D. Weygand;M. Zaiser
我们研究了晶体塑性中应力和应变模式的空间结构。为此，我们使用三种不同的模型将理论论证与塑性模拟结合起来：(i)具有局部微观结构随机演化的体晶塑性通用模型，（ii）假设体晶单滑移变形的二维离散位错模拟，以及（iii）多滑移微柱变形的三维离散位错模型。对于这三种模型，我们研究了内应力和塑性应变局部波动的尺度依赖性大小，并确定了各自自相关和相互相关函数的空间结构。研究表明，在变形过程中，应力和应变模式出现了非平凡的长程相关性。我们研究了边界条件对观察到的应力和应变空间格局的影响，并讨论了我们的发现对更大规模塑性模型的意义。
We investigate the spatial structure of stress and strain patterns in crystal plasticity. To this end, we combine theoretical arguments with plasticity simulations using three different models: (i) a generic model of bulk crystal plasticity with stochastic evolution of the local microstructure, (ii) a 2D discrete dislocation simulation assuming single-slip deformation in a bulk crystal, and (iii) a 3D discrete dislocation model for deformation of micropillars in multiple slip. For all three models we investigate the scale-dependent magnitude of local fluctuations of internal stress and plastic strain, and we determine the spatial structure of the respective auto- and cross-correlation functions. The investigations show that, in the course of deformation, nontrivial long range correlations emerge in the stress and strain patterns. We investigate the influence of boundary conditions on the observed spatial patterns of stress and strain, and discuss implications of our findings for larger-scale plasticity models.