Phase-Field Modeling of Fracture under Compression and Confinement in Anisotropic Geomaterials

Fuente: arXiv
Saved in:
Bibliographic Details
Main Authors: Hakimzadeh, Maryam, Mora-Corral, Carlos, Walkington, Noel, Buscarnera, Giuseppe, Dayal, Kaushik
Format: Preprint
Published: 2024
Subjects:
Online Access:
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866910771317833728
author Hakimzadeh, Maryam
Mora-Corral, Carlos
Walkington, Noel
Buscarnera, Giuseppe
Dayal, Kaushik
author_facet Hakimzadeh, Maryam
Mora-Corral, Carlos
Walkington, Noel
Buscarnera, Giuseppe
Dayal, Kaushik
contents Strongly anisotropic geomaterials undergo fracture under compressive loading. This paper applies a phase-field fracture model to study this fracture process. While phase-field fracture models have several advantages, they provide unphysical predictions when the stress state is complex and includes compression that can cause crack faces to contact. Building on a phase-field model that accounts for compressive traction across the crack face, this paper extends the model to anisotropic fracture. The key features include: (1) a homogenized anisotropic elastic response and strongly-anisotropic model for the work to fracture; (2) an effective damage response that accounts consistently for compressive traction across the crack face, that is derived from the anisotropic elastic response; (3) a regularized crack normal field that overcomes the shortcomings of the isotropic setting, and enables the correct crack response, both across and transverse to the crack face. To test the model, we first compare the predictions to phase-field fracture evolution calculations in a fully-resolved layered specimen with spatial inhomogeneity, and show that it captures the overall patterns of crack growth. We then apply the model to previously-reported experimental observations of fracture evolution in laboratory specimens of shales under compression with confinement, and find that it predicts well the observed crack patterns in a broad range of loading conditions. We further apply the model to predict the growth of wing cracks under compression and confinement. The effective crack response model enables us to treat the initial crack simply as a non-singular damaged zone within the computational domain, thereby allowing for easy and general computations.
format Preprint
id arxiv_https___arxiv_org_abs_2501_01468
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Phase-Field Modeling of Fracture under Compression and Confinement in Anisotropic Geomaterials
Hakimzadeh, Maryam
Mora-Corral, Carlos
Walkington, Noel
Buscarnera, Giuseppe
Dayal, Kaushik
Materials Science
Analysis of PDEs
Strongly anisotropic geomaterials undergo fracture under compressive loading. This paper applies a phase-field fracture model to study this fracture process. While phase-field fracture models have several advantages, they provide unphysical predictions when the stress state is complex and includes compression that can cause crack faces to contact. Building on a phase-field model that accounts for compressive traction across the crack face, this paper extends the model to anisotropic fracture. The key features include: (1) a homogenized anisotropic elastic response and strongly-anisotropic model for the work to fracture; (2) an effective damage response that accounts consistently for compressive traction across the crack face, that is derived from the anisotropic elastic response; (3) a regularized crack normal field that overcomes the shortcomings of the isotropic setting, and enables the correct crack response, both across and transverse to the crack face. To test the model, we first compare the predictions to phase-field fracture evolution calculations in a fully-resolved layered specimen with spatial inhomogeneity, and show that it captures the overall patterns of crack growth. We then apply the model to previously-reported experimental observations of fracture evolution in laboratory specimens of shales under compression with confinement, and find that it predicts well the observed crack patterns in a broad range of loading conditions. We further apply the model to predict the growth of wing cracks under compression and confinement. The effective crack response model enables us to treat the initial crack simply as a non-singular damaged zone within the computational domain, thereby allowing for easy and general computations.
title Phase-Field Modeling of Fracture under Compression and Confinement in Anisotropic Geomaterials
topic Materials Science
Analysis of PDEs
url https://arxiv.org/abs/2501.01468