Quantitative analysis of intrinsic mode III fatigue thresholds in bcc metals

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00216305%3A26620%2F18%3APU130263" target="_blank" >RIV/00216305:26620/18:PU130263 - isvavai.cz</a>

Nalezeny alternativní kódy

RIV/68081723:_____/18:00498397

Výsledek na webu

<a href="http://dx.doi.org/10.1016/j.ijfatigue.2018.04.022" target="_blank" >http://dx.doi.org/10.1016/j.ijfatigue.2018.04.022</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1016/j.ijfatigue.2018.04.022" target="_blank" >10.1016/j.ijfatigue.2018.04.022</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Quantitative analysis of intrinsic mode III fatigue thresholds in bcc metals

Popis výsledku v původním jazyce

Intrinsic (effective) threshold is a material characteristic important for both engineering and science connected to fatigue crack propagation processes. This paper presents the first attempt to give a quantitative interpretation of the mode III effective threshold. The approach of a local growth mode previously applied to the remote mode II cracks, which led to a prediction of values of the mode II effective threshold in metallic materials, is applied to remote mode III cracks in materials with coplanar shear-mode crack growth (bcc metals). Local mode II stress intensity factors of a zig-zag shaped crack front loaded in the remote mode III were determined by numerical modelling for various angles of in-plane crack front asperities. The results were compared with experimentally measured effective thresholds and geometry of real crack fronts. It was found that for relatively small angles of the in-plane precrack asperities (23° for the ARMCO iron and 25° for niobium) the remote mode III crack propagation can be realized purely by the local mode II growth mechanism. Experimentally measured average angles of asperities on real precrack fronts (25° for the ARMCO iron and 26° for niobium) were very close to those obtained theoretically. This represents a quantitative confirmation of a dominance of the local mode II mechanism previously deduced only qualitatively by observation of fractographical patterns.

Název v anglickém jazyce

Quantitative analysis of intrinsic mode III fatigue thresholds in bcc metals

Popis výsledku anglicky

Intrinsic (effective) threshold is a material characteristic important for both engineering and science connected to fatigue crack propagation processes. This paper presents the first attempt to give a quantitative interpretation of the mode III effective threshold. The approach of a local growth mode previously applied to the remote mode II cracks, which led to a prediction of values of the mode II effective threshold in metallic materials, is applied to remote mode III cracks in materials with coplanar shear-mode crack growth (bcc metals). Local mode II stress intensity factors of a zig-zag shaped crack front loaded in the remote mode III were determined by numerical modelling for various angles of in-plane crack front asperities. The results were compared with experimentally measured effective thresholds and geometry of real crack fronts. It was found that for relatively small angles of the in-plane precrack asperities (23° for the ARMCO iron and 25° for niobium) the remote mode III crack propagation can be realized purely by the local mode II growth mechanism. Experimentally measured average angles of asperities on real precrack fronts (25° for the ARMCO iron and 26° for niobium) were very close to those obtained theoretically. This represents a quantitative confirmation of a dominance of the local mode II mechanism previously deduced only qualitatively by observation of fractographical patterns.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

20501 - Materials engineering

Projekt

Výsledek vznikl pri realizaci vícero projektů. Více informací v záložce Projekty.

Návaznosti

P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)

Rok uplatnění

2018

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Název periodika

INTERNATIONAL JOURNAL OF FATIGUE

ISSN

0142-1123

e-ISSN

1879-3452

Svazek periodika

115

Číslo periodika v rámci svazku

1

Stát vydavatele periodika

GB - Spojené království Velké Británie a Severního Irska

Počet stran výsledku

7

Strana od-do

35-41

Kód UT WoS článku

000449895700006

EID výsledku v databázi Scopus

2-s2.0-85046668570