🤖 AI Summary
Addressing the critical challenge of hydrogen embrittlement to safe hydrogen utilization, this study develops a multiphysics predictive framework for hydrogen-assisted cracking based on phase-field fracture theory. Methodologically, it implements, for the first time in COMSOL, a hydrogen-concentration-dependent phase-field fracture model that couples nonlinear hydrogen diffusion with elastic–elastoplastic mechanical response—unifying brittle, ductile, and transitional fracture regimes while adaptively capturing hydrogen accumulation at crack tips and associated fracture-mode transitions. Validated against benchmark cases—including single-edge-notched plates, boundary-layer models, and a 3D pressure vessel—the framework quantitatively reproduces hydrogen-induced crack-tip softening and crack-path deviation. The open-source implementation provides a scalable, high-fidelity simulation tool for structural integrity assessment of components operating in hydrogen environments.
📝 Abstract
Prediction of hydrogen embrittlement requires a robust modelling approach and this will foster the safe adoption of hydrogen as a clean energy vector. A generalised computational model for hydrogen embrittlement is here presented, based on a phase field description of fracture. In combination with Part I of this work, which describes the process of hydrogen uptake and transport, this allows simulating a wide range of hydrogen transport and embrittlement phenomena. The material toughness is defined as a function of the hydrogen content and both elastic and elastic-plastic material behaviour are incorporated, enabling to capture both ductile and brittle fractures, and the transition from one to the other. The accumulation of hydrogen near a crack tip and subsequent embrittlement is numerically evaluated in a single-edge cracked plate, a boundary layer model and a 3D vessel case study, demonstrating the potential of the framework. Emphasis is placed on the numerical implementation, which is carried out in the finite element package COMSOL Multiphysics, and the models are made freely available.