Publication detail
Formulas for the critical length of mode II and III cracks emanating from circumferential U–notches
ŠANDERA, P. ŽÁK, S. HORNÍKOVÁ, J. POKLUDA, J.
English title
Formulas for the critical length of mode II and III cracks emanating from circumferential U–notches
Type
journal article in Web of Science
Language
en
Original abstract
The crack emanating from the notch reaches its critical length when the notch ceases to have effect on the crack tip stress field. In this paper a semi–empirical approach to the critical length previously proposed for mode I cracks is extended to shear–mode cracks using finite element calculations. The existing formula for the critical crack length aIc of mode I cracks emanating from circumferential U–notches in round specimens is verified also for its invariance to the specimen thickness variation and its uncertainty is quantified to be less than 1 %. This uncertainty level is then employed to obtain statistically compatible formulae for critical crack lengths aIIc and aIIIc as functions of the notch depth, the notch-root radius and the notch depth normalized to specimen thickness. These formulae are useful for a correct determination of the pre-crack length free of the notch effect in fracture toughness experiments and for a proper evaluation of stress intensity factors in experimental investigations of fatigue crack propagation.
English abstract
The crack emanating from the notch reaches its critical length when the notch ceases to have effect on the crack tip stress field. In this paper a semi–empirical approach to the critical length previously proposed for mode I cracks is extended to shear–mode cracks using finite element calculations. The existing formula for the critical crack length aIc of mode I cracks emanating from circumferential U–notches in round specimens is verified also for its invariance to the specimen thickness variation and its uncertainty is quantified to be less than 1 %. This uncertainty level is then employed to obtain statistically compatible formulae for critical crack lengths aIIc and aIIIc as functions of the notch depth, the notch-root radius and the notch depth normalized to specimen thickness. These formulae are useful for a correct determination of the pre-crack length free of the notch effect in fracture toughness experiments and for a proper evaluation of stress intensity factors in experimental investigations of fatigue crack propagation.
Keywords in English
Critical crack length; Shear modes; Stress intensity factors; U–notch
Released
11.02.2024
Publisher
Elsevier
ISSN
0013-7944
Volume
298
Number
1
Pages from–to
109955-1–109955-15
Pages count
15
BIBTEX
@article{BUT188086,
author="Pavel {Šandera} and Stanislav {Žák} and Jana {Horníková} and Jaroslav {Pokluda},
title="Formulas for the critical length of mode II and III cracks emanating from circumferential U–notches",
year="2024",
volume="298",
number="1",
month="February",
pages="109955-1--109955-15",
publisher="Elsevier",
issn="0013-7944"
}