Numerical simulations of semi-elliptical fatigue crack propagation

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00216305%3A26210%2F20%3APU143948" target="_blank" >RIV/00216305:26210/20:PU143948 - isvavai.cz</a>

Výsledek na webu

<a href="https://aip.scitation.org/doi/pdf/10.1063/5.0035558" target="_blank" >https://aip.scitation.org/doi/pdf/10.1063/5.0035558</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1063/5.0035558" target="_blank" >10.1063/5.0035558</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Numerical simulations of semi-elliptical fatigue crack propagation

Popis výsledku v původním jazyce

Residual fatigue lifetime assessment of a cracked structure is a common task for engineering and scientific community. Fatigue crack may appear on the surface or in the initial defect, e.g. pores in weldments. Such a structure needs to be examined, whether is it safe to be operated. Various assessment methods of different difficulties exist. In this paper, numerical and experimental study on fatigue crack propagation is presented. Propagation of a fatigue crack starting from an initial surface defect of semi-elliptical shape through the flat specimen is considered. Two load ratios were employed in order to compare their effects, as loading at low asymmetry R = 0.1 ensures presence of a plasticity induced crack closure, while at load ratio R = 0.6 fatigue crack growth without premature closure is expected. Beach marks were created on the fracture surface in order to study the fatigue crack evolution, number of cycles spent for fatigue growth and also the influence of premature closure on the crack front evolution. One of the well-known methods was applied for numerical fatigue lifetime evaluation and estimated number of cycles required for crack growth through the body was compared to the experimentally measured data. Second part of the paper deals with fatigue crack front curvature, which is always affected at the vicinity of the free surface due to the corner singularity of the stress field. However, when crack closure appears, fatigue crack propagation is retarded and furthermore, crack front is curved even more at the free surface as a result of earlier closure than in the middle of the body. Separation of these two effects allows direct comparison of their impact on fatigue crack front propagation.

Název v anglickém jazyce

Numerical simulations of semi-elliptical fatigue crack propagation

Popis výsledku anglicky

Residual fatigue lifetime assessment of a cracked structure is a common task for engineering and scientific community. Fatigue crack may appear on the surface or in the initial defect, e.g. pores in weldments. Such a structure needs to be examined, whether is it safe to be operated. Various assessment methods of different difficulties exist. In this paper, numerical and experimental study on fatigue crack propagation is presented. Propagation of a fatigue crack starting from an initial surface defect of semi-elliptical shape through the flat specimen is considered. Two load ratios were employed in order to compare their effects, as loading at low asymmetry R = 0.1 ensures presence of a plasticity induced crack closure, while at load ratio R = 0.6 fatigue crack growth without premature closure is expected. Beach marks were created on the fracture surface in order to study the fatigue crack evolution, number of cycles spent for fatigue growth and also the influence of premature closure on the crack front evolution. One of the well-known methods was applied for numerical fatigue lifetime evaluation and estimated number of cycles required for crack growth through the body was compared to the experimentally measured data. Second part of the paper deals with fatigue crack front curvature, which is always affected at the vicinity of the free surface due to the corner singularity of the stress field. However, when crack closure appears, fatigue crack propagation is retarded and furthermore, crack front is curved even more at the free surface as a result of earlier closure than in the middle of the body. Separation of these two effects allows direct comparison of their impact on fatigue crack front propagation.

Druh

J_SC - Článek v periodiku v databázi SCOPUS

CEP obor

—

OECD FORD obor

20301 - Mechanical engineering

Projekt

—

Návaznosti

S - Specificky vyzkum na vysokych skolach

Rok uplatnění

2020

Kód důvěrnosti údajů

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

Název periodika

AIP conference proceedings

ISSN

0094-243X

e-ISSN

—

Svazek periodika

2309

Číslo periodika v rámci svazku

-

Stát vydavatele periodika

US - Spojené státy americké

Počet stran výsledku

14

Strana od-do

1-14

Kód UT WoS článku

—

EID výsledku v databázi Scopus

2-s2.0-85098999404