Solution to the problem of low sensitivity of crack closure models to material properties

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00216305%3A26210%2F24%3APU150883" target="_blank" >RIV/00216305:26210/24:PU150883 - isvavai.cz</a>

Nalezeny alternativní kódy

RIV/68081723:_____/24:00580722

Výsledek na webu

<a href="https://www.sciencedirect.com/science/article/pii/S0167844223005062?via%3Dihub" target="_blank" >https://www.sciencedirect.com/science/article/pii/S0167844223005062?via%3Dihub</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1016/j.tafmec.2023.104243" target="_blank" >10.1016/j.tafmec.2023.104243</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Solution to the problem of low sensitivity of crack closure models to material properties

Popis výsledku v původním jazyce

The paper focuses on differences between crack closure obtained by numerical models and by experimental fatigue crack growth rates, namely for three different steels (bainitic steel, predominantly pearlitic steel and additively manufactured austenitic stainless steel). The experimental data revealed a load ratio effect different from that predicted by the most used plasticity-induced crack closure (PICC) models. The term "irreversibility of plastic deformation" was proposed in this work to be used as a material property to estimate how strong the PICC effect would be in a material. Two basic phenomena, which are usually omitted in other models, were considered in the explanation: (i) cyclic softening/hardening, (ii) brittle microcracking at the maximum load. The strip-yield model has the ability of conducting fast and accurate simulations under the variable-amplitude loading. It was demonstrated that the results of this model are practically independent of the material properties. This is caused by the consideration of only monotonic elastic-plastic material properties. To simulate real load ratio effects, the parameter beta in the strip-yield model (constraint factor in compression) is proposed to be used as a variable. It enabled a generation of different ratios of monotonic and cyclic plastic zones, which in turn helped to reproduce the crack closure values observed experimentally. Discussion and explanations were provided regarding the material microstructure. The proposed approach considers unequal tensile and compressive yield stresses caused by the different irreversibility of plastic deformation, which explains the dissimilarities in the load ratio effect observed in the investigated materials. It can also improve the accuracy of residual fatigue life estimations.

Název v anglickém jazyce

Solution to the problem of low sensitivity of crack closure models to material properties

Popis výsledku anglicky

The paper focuses on differences between crack closure obtained by numerical models and by experimental fatigue crack growth rates, namely for three different steels (bainitic steel, predominantly pearlitic steel and additively manufactured austenitic stainless steel). The experimental data revealed a load ratio effect different from that predicted by the most used plasticity-induced crack closure (PICC) models. The term "irreversibility of plastic deformation" was proposed in this work to be used as a material property to estimate how strong the PICC effect would be in a material. Two basic phenomena, which are usually omitted in other models, were considered in the explanation: (i) cyclic softening/hardening, (ii) brittle microcracking at the maximum load. The strip-yield model has the ability of conducting fast and accurate simulations under the variable-amplitude loading. It was demonstrated that the results of this model are practically independent of the material properties. This is caused by the consideration of only monotonic elastic-plastic material properties. To simulate real load ratio effects, the parameter beta in the strip-yield model (constraint factor in compression) is proposed to be used as a variable. It enabled a generation of different ratios of monotonic and cyclic plastic zones, which in turn helped to reproduce the crack closure values observed experimentally. Discussion and explanations were provided regarding the material microstructure. The proposed approach considers unequal tensile and compressive yield stresses caused by the different irreversibility of plastic deformation, which explains the dissimilarities in the load ratio effect observed in the investigated materials. It can also improve the accuracy of residual fatigue life estimations.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

20306 - Audio engineering, reliability analysis

Projekt

<a href="/cs/project/GA22-28283S" target="_blank" >GA22-28283S: Oxidy indukované zavírání trhliny a jeho dopady na únavovou životnost mechanických komponent (OXILAP)</a><br>

Návaznosti

S - Specificky vyzkum na vysokych skolach

Rok uplatnění

2024

Kód důvěrnosti údajů

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

Název periodika

THEORETICAL AND APPLIED FRACTURE MECHANICS

ISSN

0167-8442

e-ISSN

1872-7638

Svazek periodika

130

Číslo periodika v rámci svazku

104243

Stát vydavatele periodika

NL - Nizozemsko

Počet stran výsledku

12

Strana od-do

„“-„“

Kód UT WoS článku

001154966800001

EID výsledku v databázi Scopus

2-s2.0-85182023566