Publication 25-CNA-009

Crack Face Contact Modeling is Essential to Predict Crack-Parallel Stresses

Maryam Hakimzadeh
Department of Civil and Systems Engineering
Johns Hopkins University
mhakimz1@jhu.edu

Noel J. Walkington
Department of Mathematical Sciences
Carnegie Mellon University
Pittsburgh, PA 15213
noelw@andrew.cmu.edu

Carlos Mora-Corral
Departamento de Matemáticas
Universidad Autonóma de Madrid
Madrid, Spain
and
Instituto de Ciencias Matemáticas
Madrid, Spain

George Gazonas
DEVCOM Army Research Laboratory
Aberdeen Proving Ground, 21005 MD, USA

Kaushik Dayal
Department of Civil and Environmental Engineering
Center for Nonlinear Analysis
Department of Mechanical Engineering
Carnegie Mellon University
Pittsburgh, PA 15213
Kaushik.Dayal@cmu.edu

Abstract: Phase-field fracture models provide a powerful approach to modeling fracture, potentially enabling the unguided prediction of crack growth in complex patterns. To ensure that only tensile stresses and not compressive stresses drive crack growth, several models have been proposed that aim to distinguish between compressive and tensile loads. However, these models have a critical shortcoming: they do not account for the crack direction, and hence they cannot distinguish between crack-normal tensile stresses that drive crack growth and crack-parallel stresses that do not.

In this study, we apply a phase-field fracture model, developed in our earlier work, that uses the crack direction to distinguish crack-parallel stresses from crack-normal stresses. This provides a transparent energetic formulation that drives cracks to grow in when crack faces open or slide past each other, while the cracks respond like the intact solid when the crack faces contact under normal compressive loads. We compare our approach against two widely used approaches, Spectral splitting and the Volumetric-Deviatoric splitting, and find that these predict unphysical crack growth and unphysical stress concentrations under loading conditions in which these should not occur. Specifically, we show that the splitting models predict spurious crack growth and stress concentration under pure crack-parallel normal stresses. However, our formulation, which resolves the crack-parallel stresses from the crack-normal stresses, predicts these correctly.

Get the paper in its entirety as  25-CNA-009.pdf

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