多形状障碍物硬化的位错动力学计算及统一硬化模型推导

UNIFIED HARDENING MODEL AND DISLOCATION DYNAMICS ANALYSIS FOR MULTI-SHAPE OBSTACLE HARDENING

  • 摘要: 位错与辐照缺陷的相互作用会导致材料屈服强度上升,引起材料的辐照硬化。针对任意形状不可穿过缺陷引起的硬化,提出了一种统一形式的临界剪切应力预测模型。文章首先综述了现有研究中常见的球形障碍物硬化模型(Bacon-Kocks-Scattergood硬化模型),并讨论了模型在处理复杂形状障碍物时的局限性。随后,通过位错动力学模拟与线弹性理论推导,研究了位错与不同形状障碍物(包括球形、椭球形和正方体)的相互作用规律,提出了基于几何构型的统一硬化预测公式。结果表明,该线弹性模型的预测值与位错动力学计算结果吻合度较高,并能较好地预测不同形状障碍物的耦合硬化效应。该研究对改进现有硬化模型及提升辐照材料性能预测精度具有重要意义。

     

    Abstract: The interaction between dislocations and radiation-induced defects results in an increase in material yield strength, a phenomenon known as radiation hardening. This study introduces a unified model for predicting the critical resolved shear stress (CRSS) caused by impenetrable defects of arbitrary shapes.The paper begins by reviewing the commonly used spherical obstacle hardening models, such as the Bacon-Kocks-Scattergood (BKS) hardening model, discussing their limitations when applied to defects with complex geometries. It then utilizes dislocation dynamics simulations combined with linear elasticity theory to investigate the interaction between dislocations and obstacles of various shapes, including spherical, ellipsoidal, and cubic. Based on these findings, a unified hardening prediction model is developed that incorporates the geometric configuration of obstacles. The results show that the predictions of the unified hardening prediction model are in agreement with those from dislocation dynamics simulations and effectively capture the coupled hardening effects of obstacles with different shapes. This work enhances existing hardening models and improves the accuracy of radiation-induced material property predictions, offering valuable insights for the design of radiation-resistant materials.

     

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