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Computational modelling of full interaction between crystal plasticity and oxygen diffusion at a crack tip

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journal contribution
posted on 15.11.2017, 10:56 by Farukh Farukh, Liguo Zhao, N.C. Barnard, M.T. Whittaker, G. McColvin
Oxidation-promoted crack growth, one of the major concerns for nickel-based superalloys, is closely linked to the diffusion of oxygen into the crack tip. The phenomenon is still not well understood yet, especially the full interaction between oxygen diffusion and severe near-tip mechanical deformation. This work aimed at the development of a robust numerical strategy to model the full coupling of crystal plasticity and oxygen diffusion in a single crystal nickel-based superalloy. In order to accomplish this, finite element package ABAQUS is used as a platform to develop a series of user-defined subroutines to model the fully coupled process of deformation and diffusion. The formulation allowed easy incorporation of nonlinear material behaviour, various loading conditions and arbitrary model geometries. Using this method, finite element analyses of oxygen diffusion, coupled with crystal plastic deformation, were carried out to simulate oxygen penetration at a crack tip and associated change of near-tip stress field, which has significance in understanding crack growth acceleration in oxidation environment. Based on fully coupled diffusion-deformation analyses, a case study was carried out to predict crack growth rate in oxidation environment and under dwell-fatigue loading conditions, for which a twoparameter failure criterion, in terms of accumulated inelastic strain and oxygen concentration at the crack tip, has been utilized.

Funding

The work was funded by the EPSRC (Grants EP/K026844/1 and EP/ M000966/1) of the UK and in collaboration with Universities of Southampton and Warwick (UK), Nasa, GE Power, Uniper and Dstl.

History

School

  • Mechanical, Electrical and Manufacturing Engineering

Published in

Theoretical and Applied Fracture Mechanics

Citation

FARUKH, F. ... et al., 2017. Computational modelling of full interaction between crystal plasticity and oxygen diffusion at a crack tip. Theoretical and Applied Fracture Mechanics, 96, pp. 707-719.

Publisher

© 2017 The Authors. Published by Elsevier Ltd.

Version

VoR (Version of Record)

Publisher statement

This work is made available according to the conditions of the Creative Commons Attribution 4.0 International (CC BY 4.0) licence. Full details of this licence are available at: http://creativecommons.org/licenses/ by/4.0/

Acceptance date

31/10/2017

Publication date

2017-11-01

Notes

This is an open access article under the CC BY license (http://creativecommons.org/licenses/BY/4.0/).

ISSN

0167-8442

Language

en

Licence

Exports