A weakly coupled implementation of hydrogen embrittlement in FE analysis

The paper presents a numerical code for the simulation of hydrogen embrittlement. The aim is to provide a guideline to the methodology but also to its practical use. The code, implemented within the commercial software Abaqus, presents a three-step procedure that weakly couples hydrogen diffusion with stress–strain analysis: an initial static analysis, a mass diffusion analysis, and a final static analysis with the cohesive zone modelling approach. Cohesive elements offer a customizable formulation within the standard finite element framework, and are suitable to simulate failure of the material (i. e. a crack) in presence of environmental hydrogen uptake. The formulation of cohesive elements is implemented considering a mechanism of local decohesion with an extensive use of Abaqus user subroutines. Examples of the code application to simple models and to a real specimen are included to support as well as to make the findings of the paper fully replicable. All the subroutines and the examples are released in open source form under the webpage of the project, named PoliHydra.