A generalised framework for phase field-based modelling of coupled problems: application to thermo-mechanical fracture, hydraulic fracture, hydrogen embrittlement and corrosion

TL;DR

This paper introduces a versatile, generalised phase field framework for modeling coupled multi-physics problems in structural integrity, demonstrated through applications to fracture, embrittlement, and corrosion, with implementation in Abaqus.

Contribution

It develops a unified, easily integrable phase field approach for complex coupled problems, applicable to various engineering issues, and provides open-source computational tools.

Findings

Accurate modeling of thermo-mechanical fracture, hydraulic fracture, hydrogen embrittlement, and corrosion.

Good agreement with experimental and analytical solutions.

Implementation in commercial finite element software demonstrated.

Abstract

We present a novel, generalised formulation to treat coupled structural integrity problems by combining phase field and multi-physics modelling. The approach exploits the versatility of the heat transfer equation and is therefore well suited to be adopted in commercial finite element packages, requiring only integration point-level implementation. This aspect is demonstrated here by implementing coupled, multi-variable phenomena through simple \texttt{UMAT} and \texttt{UMATHT} subroutines in the finite element package \texttt{Abaqus}. The generalised theoretical and computational framework presented is particularised to four problems of engineering and scientific relevance: thermo-mechanical fracture, hydraulic fracture, hydrogen-assisted cracking and metallic corrosion. 2D and 3D problems are considered. The results reveal a very good agreement with experimental data, and existing numerical and analytical solutions.The user subroutines developed are made freely available at https://mechmat.web.ox.ac.uk/codes.