Sustainable Marine Structures

Finite Element Modelling of Hydrogen Embrittlement by Considering Hydrogen Coverage Boundary Conditions

Dario Gravina

Department of Naval Architecture, Ocean and Marine Engineering, University of Strathclyde, G4 0LZ Glasgow, UK

Selda Oterkus

University of Strathclyde

Erkan Oterkus

Department of Naval Architecture, Ocean and Marine Engineering, University of Strathclyde, G4 0LZ Glasgow, UK

DOI: https://doi.org/10.36956/sms.v7i4.2617

Received: 10 August 2025; Published: 24 December 2025

Abstract

In this study, an alternative modelling approach for absorbed hydrogen stress corrosion cracking (SCC) is proposed, with hydrogen-enhanced decohesion (HEDE) identified as the key failure mechanism. All analyses have been performed by utilising only ABAQUS standard elements, COH2D4T and CPE4T, already available within the software and without the need to develop external subroutines. The study also tends to highlight the criticality of implementing a correct Traction Separation Law (TSL) curve to simulate the hydrogen diffusion within the specimen and using the concept of dynamic hydrogen penetration by continuously updating the hydrogen concentration boundary conditions as the crack propagates. In conclusion, this study successfully demonstrated that standard software elements (COH2D4T and CPE4T) can effectively model physical problems and crack velocity propagation without custom subroutines. It emphasized that while the specific shape of the Traction-Separation Law (TSL) is less critical, its correct implementation is vital for simulating dynamic hydrogen coverage. Crucially, excluding this dynamic coverage—a common practice—risks significantly underestimating crack propagation speed. Although results incorporating dynamic coverage aligned well with experimental data, minor discrepancies are likely due to unmodeled factors like material property variations, hydrogen trapping, temperature, and granular microstructure, which are proposed for future research.

Keywords: Hydrogen Embrittlement, Finite Element Method, Cohesive Zone Model, Stress Corrosion Cracking, Fracture

References