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Review of fatigue crack growth under non-proportional loading

Vormwald, Michael and Zerres, Patrick (2012):
Review of fatigue crack growth under non-proportional loading.
In: The 4th Int. Conf. on Crack Paths, ISBN 9788895940441,
[Conference or Workshop Item]

Abstract

Cyclic non-proportional loading is common experimental practise for investigations of large structures like vehicles. Numerical analysis of local nonproportional loading conditions is also a well established field of research and application. However, theoretical and practical support is rare for evaluating the growth of fatigue cracks under non-proportional cyclic loading conditions. At least seven influence factors – most of them not yet throroughly understood – are listed and discussed in the paper: the mode-mixity, the material’s influence including its anisotropy if existant, the degree of cyclic plastic deformation and its direction ahead of the crack tip, the crack closure phenomenon, the related mean stress effect, the component’s geometry in general and especially the variable mode-mixity along a crack front. Two crack propagation mechanisms must be considered: The tensile stress dominated, mode II minimising mechanism and the shear stess dominated mechanism. Transition mode-mixities are observed. Some successful explanations of experimental findings have been published, however, a generally accepted and validated formulation of a crack driving force parameter is out of sight.

Item Type: Conference or Workshop Item
Erschienen: 2012
Creators: Vormwald, Michael and Zerres, Patrick
Title: Review of fatigue crack growth under non-proportional loading
Language: English
Abstract:

Cyclic non-proportional loading is common experimental practise for investigations of large structures like vehicles. Numerical analysis of local nonproportional loading conditions is also a well established field of research and application. However, theoretical and practical support is rare for evaluating the growth of fatigue cracks under non-proportional cyclic loading conditions. At least seven influence factors – most of them not yet throroughly understood – are listed and discussed in the paper: the mode-mixity, the material’s influence including its anisotropy if existant, the degree of cyclic plastic deformation and its direction ahead of the crack tip, the crack closure phenomenon, the related mean stress effect, the component’s geometry in general and especially the variable mode-mixity along a crack front. Two crack propagation mechanisms must be considered: The tensile stress dominated, mode II minimising mechanism and the shear stess dominated mechanism. Transition mode-mixities are observed. Some successful explanations of experimental findings have been published, however, a generally accepted and validated formulation of a crack driving force parameter is out of sight.

Title of Book: The 4th Int. Conf. on Crack Paths
ISBN: 9788895940441
Divisions: 13 Department of Civil and Environmental Engineering Sciences
13 Department of Civil and Environmental Engineering Sciences > Institute of Steel Constructions and Material Mechanics
13 Department of Civil and Environmental Engineering Sciences > Institute of Steel Constructions and Material Mechanics > Fachgebiet Werkstoffmechanik
Date Deposited: 30 Jan 2015 13:22
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