Dislocations can provide short circuit diffusion paths for atoms resulting in a dislocation climb motion referred to as self-climb. A variational principle is presented for the analysis of problems in which fast dislocation core diffusion is the dominant mechanism for material redistribution. The linear element based self-climb model, developed in our previous work [1] Liu, Cocks and Tarleton (2020 J. Mech. Phys. Solids 135 103783), is significantly accelerated here, by employing a new finite element discretisation method. The speed-up in computation enables us to use the self-climb model as an effective numerical technique to simulate emergent dislocation behaviour involving both self-climb and glide. The formation of prismatic loops from the break-up of different types of edge dislocation dipoles are investigated based on this new method. We demonstrate that edge dipoles sequentially pinch-off prismatic loops, rather than spontaneously breaking-up into a string of loops, to rapidly decrease the total dislocation energy.

中文翻译：

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位错自爬模型的改进方法

位错可以为原子提供短路扩散路径，从而导致称为自攀爬的位错攀爬运动。提出了一种变分原理，用于分析快速位错核扩散是材料再分布的主要机制的问题。在我们之前的工作 [1] Liu、Cocks 和 Tarleton (2020 J. Mech. Phys. Solids 135 103783) 中开发的基于线性单元的自爬模型在这里通过采用新的有限元离散化方法得到显着加速。计算的加速使我们能够使用自爬模型作为一种有效的数值技术来模拟涉及自爬和滑行的紧急位错行为。基于这种新方法，研究了由不同类型的边缘位错偶极子破裂而形成的棱柱环。