Publication detail
Equations for efficient cycle-by-cycle computation of fatigue crack retardation and acceleration due to amplitude changes
KUBÍČEK, R. VOJTEK, T. POKORNÝ, P. NÁHLÍK, L. HUTAŘ, P.
English title
Equations for efficient cycle-by-cycle computation of fatigue crack retardation and acceleration due to amplitude changes
Type
journal article in Web of Science
Language
en
Original abstract
The paper presents an efficient methodology for computation of the evolution of the fatigue crack retardation and acceleration effects due to crack closure during variable amplitude loading. The presented approach can lead to a very effective tool for estimation of residual fatigue life of engineering structures. Conventionally, consideration of variable-amplitude loading is either computationally too demanding, such as in finite element modelling, or challenging to unify the strip-yield model with another computational code. The simple analytical formulae available in literature are based on residual stress, which does not describe correctly the delayed retardation effect and in some cases it can be non-conservative. This work presents simple analytical equations describing the development of the crack closure based on the results of the strip-yield model for amplitude changes at the load ratio R = 0.1. The parabolic function enables simple computation of the maximum crack closure occurring after an overload without running any simulation. The equations also enable computation of crack closure behaviour following amplitude changes with the consideration of various cyclic material properties reflected in the tuneable ratio between the monotonic and cyclic plastic zone sizes.
English abstract
The paper presents an efficient methodology for computation of the evolution of the fatigue crack retardation and acceleration effects due to crack closure during variable amplitude loading. The presented approach can lead to a very effective tool for estimation of residual fatigue life of engineering structures. Conventionally, consideration of variable-amplitude loading is either computationally too demanding, such as in finite element modelling, or challenging to unify the strip-yield model with another computational code. The simple analytical formulae available in literature are based on residual stress, which does not describe correctly the delayed retardation effect and in some cases it can be non-conservative. This work presents simple analytical equations describing the development of the crack closure based on the results of the strip-yield model for amplitude changes at the load ratio R = 0.1. The parabolic function enables simple computation of the maximum crack closure occurring after an overload without running any simulation. The equations also enable computation of crack closure behaviour following amplitude changes with the consideration of various cyclic material properties reflected in the tuneable ratio between the monotonic and cyclic plastic zone sizes.
Keywords in English
Variable amplitude loading; Plasticity induced crack closure; Strip-yield model; Steel
Released
01.10.2024
Publisher
ELSEVIER
Location
AMSTERDAM
ISSN
0167-8442
Volume
133
Number
104547
Pages count
13
BIBTEX
@article{BUT189354,
author="Radek {Kubíček} and Tomáš {Vojtek} and Pavel {Pokorný} and Luboš {Náhlík} and Pavel {Hutař},
title="Equations for efficient cycle-by-cycle computation of fatigue crack retardation and acceleration due to amplitude changes",
year="2024",
volume="133",
number="104547",
month="October",
publisher="ELSEVIER",
address="AMSTERDAM",
issn="0167-8442"
}