发表机构
Jiangnan University; Jiangsu Key Laboratory of Advanced Food Manufacturing Equipment and Technology（江南大学; 江苏省先进食品加工装备与技术重点实验室）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
针对氢环境下裂纹尖端位错发射，提出氢影响的Rice-Beltz模型，量化混合模式加载下临界应力强度因子，揭示氢浓度非单调影响，为氢致塑性提供无参数边界条件。
AI 中文摘要
裂纹尖端解理与位错发射之间的基本竞争决定了晶体固体中的韧脆转变。在充氢环境中，这种微妙的平衡被打破，然而现有模型往往难以自洽地捕捉发射势垒的原子尺度热力学调制。在此，我们提出氢影响的Rice-Beltz框架，用于量化混合模式（I+II）加载下初始位错形核所需的临界应力强度因子（SIF）。通过整合间隙氢的膨胀场与施加应力场对初始位错芯的弹性相互作用，该模型恢复了最可能SIF与氢浓度之间的非单调关系。与经典纯I型（或II型）情形不同，采用局部应变能密度最小化来生成闭式名义驱动力，随后将其嵌入过渡态理论框架。这种原子级信息方法给出了首次位错发射事件的最可能SIF，作为加载速率、滑移角和氢浓度的函数，为氢调制的裂纹尖端塑性的起始提供了严格、无参数的边界条件。
英文摘要
The fundamental competition between crack-tip cleavage and dislocation emission dictates the ductile-to-brittle transition in crystalline solids. In hydrogen-charged environments, this delicate balance is disrupted, yet existing models often struggle to self-consistently capture the atomic-scale thermomechanical modulation of the emission barrier. Here, we propose the hydrogen-informed Rice-Beltz framework to quantify the critical stress intensity factors (SIFs) required for initial dislocation nucleation under mixed-mode (I+II) loading. By integrating the elastic interaction of the dilatational field of interstitial hydrogen and the applied stress fields against the incipient dislocation core, the model recovers the non-monotonic relation between the most probable SIF and the hydrogen concentration. Unlike the classical pure mode-I (or mode-II) scenario, the minimization of the local strain energy density is employed to generate closed-form nominal driving forces, which are subsequently embedded into a transition-state-theory framework. This atomistically-informed approach yields the most probable SIF for the first dislocation emission event as a function of the loading rate, slip angle, and hydrogen concentration, providing a rigorous, parameter-free boundary condition for the onset of hydrogen-modulated crack-tip plasticity.
Journal refK. Zhao Mechanics of Materials 223 (2026) 105876
DOI：10.1016/j.mechmat.2026.105876
