Publication detail

On the connection between mode II and mode III effective thresholds in metals

VOJTEK, T. ŽÁK, S. POKLUDA, J.

Original Title

On the connection between mode II and mode III effective thresholds in metals

English Title

On the connection between mode II and mode III effective thresholds in metals

Type

journal article in Web of Science

Language

en

Original Abstract

Closure-free long cracks under the remote mode III loading grow in a more complicated way than those under the remote mode II. For bcc metals, a coplanar in-plane spreading of tongues driven by the local mode II loading components at crack-front asperities prevails while twisting of crack-front segments to mode I, often leading to factory-roof morphology, is typical for other materials. In bcc metals, therefore, the formulation of a quantitative relationship connecting effective thresholds in modes II and III demands to calculate the local mode II components of stress intensity factors at typical asperities of a crack front loaded in the remote mode III. Therefore, a numerical model of a serrated crack front was created and the results were compared with experimentally determined ratio of mode II and III effective thresholds for the ARMCO iron. Although the calculated crack-front roughness needs an experimental verification, the preliminary results indicate that the model can provide a quantitative explanation of the experimentally observed ratio of mode II and mode III effective thresholds in bcc metals.

English abstract

Closure-free long cracks under the remote mode III loading grow in a more complicated way than those under the remote mode II. For bcc metals, a coplanar in-plane spreading of tongues driven by the local mode II loading components at crack-front asperities prevails while twisting of crack-front segments to mode I, often leading to factory-roof morphology, is typical for other materials. In bcc metals, therefore, the formulation of a quantitative relationship connecting effective thresholds in modes II and III demands to calculate the local mode II components of stress intensity factors at typical asperities of a crack front loaded in the remote mode III. Therefore, a numerical model of a serrated crack front was created and the results were compared with experimentally determined ratio of mode II and III effective thresholds for the ARMCO iron. Although the calculated crack-front roughness needs an experimental verification, the preliminary results indicate that the model can provide a quantitative explanation of the experimentally observed ratio of mode II and mode III effective thresholds in bcc metals.

Keywords

Modes II and III; Effective threshold; Micromechanism; Finite element method; ARMCO iron

Released

01.07.2017

Publisher

Italian Group of Fracture

ISBN

1971-8993

Periodical

Frattura ed Integrita Strutturale

Year of study

11

Number

41

State

IT

Pages from

245

Pages to

251

Pages count

7

URL

Full text in the Digital Library

Documents

BibTex


@article{BUT142361,
  author="Tomáš {Vojtek} and Stanislav {Žák} and Jaroslav {Pokluda}",
  title="On the connection between mode II and mode III effective thresholds in metals",
  annote="Closure-free long cracks under the remote mode III loading grow in a more complicated way than those under the remote mode II. For bcc metals, a coplanar in-plane spreading of tongues driven by the local mode II loading components at crack-front asperities prevails while twisting of crack-front segments to mode I, often leading to factory-roof morphology, is typical for other materials. In bcc metals, therefore, the formulation of a quantitative relationship connecting effective thresholds in modes II and III demands to calculate the local mode II components of stress intensity factors at typical asperities of a crack front loaded in the remote mode III. Therefore, a numerical model of a serrated crack front was created and the results were compared with experimentally determined ratio of mode II and III effective thresholds for the ARMCO iron. Although the calculated crack-front roughness needs an experimental verification, the preliminary results indicate that the model can provide a quantitative explanation of the experimentally observed ratio of mode II and mode III effective thresholds in bcc metals.",
  address="Italian Group of Fracture",
  chapter="142361",
  doi="10.3221/IGF-ESIS.41.33",
  institution="Italian Group of Fracture",
  number="41",
  volume="11",
  year="2017",
  month="july",
  pages="245--251",
  publisher="Italian Group of Fracture",
  type="journal article in Web of Science"
}