We present a new theoretical and numerical phase field-based formulation for predicting hydrogen-assisted fatigue. The coupled deformation-diffusion-damage model presented enables predicting fatigue crack nucleation and growth for arbitrary loading patterns and specimen geometries. The role of hydrogen in increasing fatigue crack growth rates and decreasing the number of cycles to failure is investigated. Our numerical experiments enable mapping the three loading frequency regimes and naturally recover Paris law behaviour for various hydrogen concentrations. In addition, Virtual S–N curves are obtained for both notched and smooth samples, exhibiting a good agreement with experiments.

我们提出了一种新的基于理论和数值相场的公式，用于预测氢辅助疲劳。提出的耦合变形-扩散-损伤模型能够预测任意加载模式和试样几何形状的疲劳裂纹成核和增长。研究了氢在增加疲劳裂纹扩展速率和减少失效循环次数方面的作用。我们的数值实验能够绘制三个加载频率范围，并自然地恢复各种氢浓度的巴黎定律行为。此外，获得了缺口和光滑样品的虚拟S-N 曲线，与实验表现出良好的一致性。