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"
}