Near-threshold behaviour of shear-mode fatigue cracks in metallic materials

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00216305%3A26620%2F14%3APU106533" target="_blank" >RIV/00216305:26620/14:PU106533 - isvavai.cz</a>

Výsledek na webu

<a href="http://dx.doi.org/10.1111/ffe.12131" target="_blank" >http://dx.doi.org/10.1111/ffe.12131</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1111/ffe.12131" target="_blank" >10.1111/ffe.12131</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Near-threshold behaviour of shear-mode fatigue cracks in metallic materials

Popis výsledku v původním jazyce

This review paper presents a brief state-of-the art of the research on long fatigue shearmode cracks and describes some recent results on effective crack growth thresholds and mode I branching conditions achieved by the authors for ARMCO iron, titanium with two different microstructures, nickel and stainless steel. A special technique for preparation of fatigue precracks enabled us to substantially suppress the crack closure (friction) effects at the beginning of the experiment, and the measured threshold values could be considered to be very close to the effective ones. In all investigated materials, the effective thresholds under the remote mode II loading were found to be about 1.7 times lower than those under the remote mode III loading. Effective thresholds under mode II loading of investigated materials were found to follow a simple formula assembled by the shear modulus G, the magnitude of Burgers vector b and a goniometrical function of the mean deflection angle that depends on the number of available crystallographic slip systems. These quantities determine the intrinsic material resistance to mode II crack propagation at the threshold. A simple criterion for mode I branching in terms of effective threshold values well reflects a transition from the shear-mode to the opening-mode controlled crack propagation at the threshold. The associated transition deflection angle of 40 degrees is a material independent constant.

Název v anglickém jazyce

Near-threshold behaviour of shear-mode fatigue cracks in metallic materials

Popis výsledku anglicky

This review paper presents a brief state-of-the art of the research on long fatigue shearmode cracks and describes some recent results on effective crack growth thresholds and mode I branching conditions achieved by the authors for ARMCO iron, titanium with two different microstructures, nickel and stainless steel. A special technique for preparation of fatigue precracks enabled us to substantially suppress the crack closure (friction) effects at the beginning of the experiment, and the measured threshold values could be considered to be very close to the effective ones. In all investigated materials, the effective thresholds under the remote mode II loading were found to be about 1.7 times lower than those under the remote mode III loading. Effective thresholds under mode II loading of investigated materials were found to follow a simple formula assembled by the shear modulus G, the magnitude of Burgers vector b and a goniometrical function of the mean deflection angle that depends on the number of available crystallographic slip systems. These quantities determine the intrinsic material resistance to mode II crack propagation at the threshold. A simple criterion for mode I branching in terms of effective threshold values well reflects a transition from the shear-mode to the opening-mode controlled crack propagation at the threshold. The associated transition deflection angle of 40 degrees is a material independent constant.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

20306 - Audio engineering, reliability analysis

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

2014

Kód důvěrnosti údajů

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

Název periodika

Fatigue & Fracture of Engineering Materials & Structures

ISSN

8756-758X

e-ISSN

1460-2695

Svazek periodika

37

Číslo periodika v rámci svazku

3

Stát vydavatele periodika

US - Spojené státy americké

Počet stran výsledku

23

Strana od-do

232-254

Kód UT WoS článku

000331386700002

EID výsledku v databázi Scopus

2-s2.0-84893845141