A continuum model for numerical simulation of hydrogen induced embrittlement of pipeline material is discussed within this work. For that, a transient hydrogen model considering trapping is coupled with an elasto-plastic material model considering von Mises yielding. The hydrogen enhanced plasticity (HELP) mechanism is assumed to be active within this problem statement and is realized by a hydrogen dependent reduction of the yield strength. An iterative numerical solution scheme is applied to solve the coupled problem. At the example of a pipeline with a blunted crack, the influence of hydrogen is investigated. A localized plastic zone is observed for high hydrogen concentrations, in line with the inherent phenomena of the HELP mechanism. However, when applying hydrogen boundary conditions which are considered to be realistic for an existing natural gas pipeline, no pronounced effect of hydrogen based on reducing the yield strength could be observed. Nevertheless, this numerical results do not imply a judgment if the HELP mechanism in general could be the prevalent mechanism for failure.
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