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

2025-06-25

AI Summary

Material fracture under coupled multiphysics fields—such as thermo-mechanical, fluid–structure, hydrogen diffusion, and corrosion—remains a significant challenge in computational mechanics. Method: This paper proposes a general phase-field fracture modeling paradigm that enables multiphysics coupling via analogy to the heat conduction equation. The framework supports 2D/3D finite element implementation within Abaqus through user-defined subroutines (UMAT/UMATHT), offering integration-point-level customization and seamless compatibility with commercial software. Contribution/Results: It establishes the first unified, modular, and open-source phase-field framework for multiphysics fracture analysis, covering thermo-mechanical fracture, hydraulic fracturing, hydrogen-assisted cracking, and stress corrosion cracking. Numerical results demonstrate excellent agreement with experimental data and analytical solutions, validating its accuracy, robustness, and engineering applicability. The open-source implementation promotes standardization of phase-field methods for fracture simulation under complex service conditions.

Technology Category

• Constraint Satisfaction and Optimization: Satisfiability Modulo Theories
• Computer Vision: Low Level & Physics-based Vision
• Search and Optimization: Mixed Discrete/Continuous Search

Application Category

• User Modeling, Personalization and Recommendation: User modeling and simulation for interactive and conversational systems
• Systems and Infrastructure for Web, Mobile and WoT: Web applications in cross-disciplinary domains and verticals such as mixed reality, smart cities, and digital health
• Search and Retrieval-Augmented AI: Retrieval-Augmented Generation (RAG) and multi-modal RAG

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 exttt{UMAT} and exttt{UMATHT} subroutines in the finite element package exttt{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.

Problem

• Develops a generalized phase field framework for coupled structural integrity problems
• Applies framework to thermo-mechanical and hydraulic fracture, hydrogen embrittlement, corrosion
• Implements model in commercial FEM software via user subroutines (UMAT/UMATHT)

Innovation

• Generalized phase field and multi-physics modeling
• Heat transfer equation-based versatile approach
• Integration point-level UMAT and UMATHT implementation