Publication detail

Numerical modelling of fatigue crack closure and its implication on crack front curvature using ΔCTODp

OPLT, T. VOJTEK, T. KUBÍČEK, R. POKORNÝ, P. HUTAŘ, P.

Original Title

Numerical modelling of fatigue crack closure and its implication on crack front curvature using ΔCTODp

Type

journal article in Web of Science

Language

English

Original Abstract

One of the widely used approaches to characterize fatigue crack propagation is the use of the effective stress intensity factor range ΔKeff, which relies on determination of crack closure value Kcl. The used models of crack closure are most frequently-two-dimensional, however, for real cracks, the 3D effects should be taken into ac-count. The paper presents 3D finite element analyses of the influences of crack front shape, inserted cycles (loading cycles between node releases) and crack closure on the crack driving force in terms of ΔKeff and ΔCTODp (plastic part of crack tip opening displacement range). Numerically obtained crack closure depended on the simulation strategy. In the case of inserted cycles, crack closure disappeared in the internal part of the specimen and remained only near the free edges. The use of ΔCTODp had the advantage of a well-defined parameter in situations where ΔKeff was problematic, namely at the corner points, which did not allow finding of equalized crack driving force along the whole crack front using ΔKeff. Equalized crack driving force in terms of ΔCTODp was found for crack front curvature with the edge angle 15.4 degrees in simulation with crack closure, which was in good agreement with the experimentally measured value of 16 degrees. Loops produced by loading and unloading branches of the force vs CTOD diagrams helped to describe the crack closure process and magnitude. Actual values of CTOD did not agree with the classical idea of 2D solutions under plane strain and plane stress. CTOD was larger in the internal part of the specimen than at the free edges, even in simulations with no crack face contact.

Keywords

Crack front curvature; CTOD; Crack closure; Finite element modelling; Steel

Authors

OPLT, T.; VOJTEK, T.; KUBÍČEK, R.; POKORNÝ, P.; HUTAŘ, P.

Released

22. 2. 2023

Publisher

ELSEVIER LTD

ISBN

1879-3452

Periodical

INTERNATIONAL JOURNAL OF FATIGUE

Year of study

171

Number

107570

State

United Kingdom of Great Britain and Northern Ireland

Pages count

13

URL

https://www.sciencedirect.com/science/article/pii/S0142112323000713?via%3Dihub

BibTex

@article{BUT187982,
  author="Tomáš {Oplt} and Tomáš {Vojtek} and Radek {Kubíček} and Pavel {Pokorný} and Pavel {Hutař}",
  title="Numerical modelling of fatigue crack closure and its implication on crack front curvature using ΔCTODp",
  journal="INTERNATIONAL JOURNAL OF FATIGUE",
  year="2023",
  volume="171",
  number="107570",
  pages="13",
  doi="10.1016/j.ijfatigue.2023.107570",
  issn="1879-3452",
  url="https://www.sciencedirect.com/science/article/pii/S0142112323000713?via%3Dihub"
}