A theoretical and computational framework for studying creep crack growth

In this study, crack growth under steady state creep conditions is analysed. A theoretical framework is introduced in which the constitutive behaviour of the bulk material is described by power-law creep. A new class of damage zone models is proposed to model the fracture process ahead of a crack ti...

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Hauptverfasser: Elmukashfi, E, Cocks, A
Format: Journal article
Veröffentlicht: Springer 2017
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author Elmukashfi, E
Cocks, A
author_facet Elmukashfi, E
Cocks, A
author_sort Elmukashfi, E
collection OXFORD
description In this study, crack growth under steady state creep conditions is analysed. A theoretical framework is introduced in which the constitutive behaviour of the bulk material is described by power-law creep. A new class of damage zone models is proposed to model the fracture process ahead of a crack tip, such that the constitutive relation is described by a tractionseparation rate law. In particular, simple critical displacement, empirical Kachanov type damage and micromechanical based interface models are used. Using the path independency property of the C∗-integral and dimensional analysis, analytical models are developed for pure mode-I steady-state crack growth in a double cantilever beam specimen (DCB) subjected to constant pure bending moment. A computational framework is then implemented using the Finite Element method. The analytical models are calibrated against detailed Finite Element models. The theoretical framework gives the fundamental form of the model and only a single quantity Ck needs to be determined from the Finite Element analysis in terms of a dimensionless quantity 𝜙0, which is the ratio of geometric and material length scales. Further, the validity of the framework is examined by investigating the crack growth response in the limits of small and large 𝜙0, for which analytical expression can be obtained. We also demonstrate how parameters within the models can be obtained from creep deformation, creep rupture and crack growth experiments.
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spelling oxford-uuid:bc20edff-1adc-4eff-b966-f40d819ca3d72022-03-27T05:22:08ZA theoretical and computational framework for studying creep crack growthJournal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:bc20edff-1adc-4eff-b966-f40d819ca3d7Symplectic Elements at OxfordSpringer2017Elmukashfi, ECocks, AIn this study, crack growth under steady state creep conditions is analysed. A theoretical framework is introduced in which the constitutive behaviour of the bulk material is described by power-law creep. A new class of damage zone models is proposed to model the fracture process ahead of a crack tip, such that the constitutive relation is described by a tractionseparation rate law. In particular, simple critical displacement, empirical Kachanov type damage and micromechanical based interface models are used. Using the path independency property of the C∗-integral and dimensional analysis, analytical models are developed for pure mode-I steady-state crack growth in a double cantilever beam specimen (DCB) subjected to constant pure bending moment. A computational framework is then implemented using the Finite Element method. The analytical models are calibrated against detailed Finite Element models. The theoretical framework gives the fundamental form of the model and only a single quantity Ck needs to be determined from the Finite Element analysis in terms of a dimensionless quantity 𝜙0, which is the ratio of geometric and material length scales. Further, the validity of the framework is examined by investigating the crack growth response in the limits of small and large 𝜙0, for which analytical expression can be obtained. We also demonstrate how parameters within the models can be obtained from creep deformation, creep rupture and crack growth experiments.
spellingShingle Elmukashfi, E
Cocks, A
A theoretical and computational framework for studying creep crack growth
title A theoretical and computational framework for studying creep crack growth
title_full A theoretical and computational framework for studying creep crack growth
title_fullStr A theoretical and computational framework for studying creep crack growth
title_full_unstemmed A theoretical and computational framework for studying creep crack growth
title_short A theoretical and computational framework for studying creep crack growth
title_sort theoretical and computational framework for studying creep crack growth
work_keys_str_mv AT elmukashfie atheoreticalandcomputationalframeworkforstudyingcreepcrackgrowth
AT cocksa atheoreticalandcomputationalframeworkforstudyingcreepcrackgrowth
AT elmukashfie theoreticalandcomputationalframeworkforstudyingcreepcrackgrowth
AT cocksa theoreticalandcomputationalframeworkforstudyingcreepcrackgrowth