Computational predictions of hydrogen-assisted fatigue crack growth

Journal article

A new model is presented to predict hydrogen-assisted fatigue. The model combines a phase field description of fracture and fatigue, stress-assisted hydrogen diffusion, and a toughness degradation formulation with cyclic and hydrogen contributions. Hydrogen-assisted fatigue crack growth predictions exhibit an excellent agreement with experiments over all the scenarios considered, spanning multiple load ratios, H pressures and loading frequencies. These are obtained without any calibration with hydrogen-assisted fatigue data, taking as input only mechanical and hydrogen transport material properties, the material’s fatigue characteristics (from a single test in air), and the sensitivity of fracture toughness to hydrogen content. Furthermore, the model is used to determine: (i) what are suitable test loading frequencies to obtain conservative data, and (ii) the underestimation made when not pre-charging samples. The model can handle both laboratory specimens and large-scale engineering components, enabling the Virtual Testing paradigm in infrastructure exposed to hydrogen environments and cyclic loading.

Authors: Cui, C; Bortot, P; Ortolani, M; Martínez-Pañeda, E

• Publication status: Published
• Peer review status: Peer reviewed
• Publisher: Elsevier
• Journal: International Journal of Hydrogen Energy
• Volume: 72
• Pages: 315-325
• Publication date: 2024-05-29
• Acceptance date: 2024-05-17
• DOI: 10.1016/j.ijhydene.2024.05.264
• EISSN: 1879-3487
• ISSN: 0360-3199
• Language: English
• Keywords: phase field; finite element analysis; fatigue crack growth rates; hydrogen storage; hydrogen embrittlement; Paris law