This study proposes a new elastic–plastic deformation decomposition algorithm for metal clusters to calculate micro-nanoscale elastic and plastic deformation gradients. In the macroscopic plasticity theory, the intermediate configuration is usually constructed by the dissection–unloading method. Because an atomic cluster is equivalent to a small element on a macroscopic object, our decomposition algorithm regards the unloaded configuration as the intermediate configuration for atomic clusters. This algorithm uses a new unloading method to obtain the unloaded configuration. This micro-nanoscale unloading method is constructed based on the principle of minimum potential energy and the embedded-atom method. Moreover, this method rigidly fixes atoms around dislocations during unloading. Therefore, the unloading process will not cause new plastic flow. Once the intermediate configuration is obtained, elastic and plastic deformation gradients are calculated by the interpolation method. Numerical examples of Cu nanowire stretching and bending show that the new decomposition algorithm can accurately and rapidly conduct the elastic–plastic decomposition of the total deformation. This algorithm provides a computational basis for multiscale coupling analysis of mechanical behavior of metal materials from the micro-nanoscale to the macroscale.

中文翻译：

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原子尺度金属簇弹塑性变形分解算法

本研究提出了一种新的金属簇弹塑性变形分解算法，用于计算微纳米尺度的弹塑性变形梯度。在宏观塑性理论中，中间构型通常是通过解剖-卸载方法构建的。由于原子簇相当于宏观物体上的一个小元素，我们的分解算法将卸载的配置视为原子簇的中间配置。该算法使用新的卸载方法来获取卸载的配置。这种微纳米级卸载方法是基于最小势能原理和嵌入原子方法构建的。此外，这种方法在卸载过程中严格地将原子固定在位错周围。因此，卸载过程不会引起新的塑性流动。一旦获得中间配置，弹性和塑性变形梯度就通过插值法计算出来。Cu纳米线拉伸和弯曲的数值例子表明，新的分解算法可以准确快速地进行总变形的弹塑性分解。该算法为金属材料从微纳米尺度到宏观尺度的力学行为的多尺度耦合分析提供了计算基础。