Fatigue crack propagation analysis in 2024-T351 aluminium alloy using nonlinear parameters
| Autor: | B. Moreno, M.F. Borges, Fernando Antunes, Pedro Prates, D. Camas, Diogo M. Neto, Pablo Lopez-Crespo |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2021 |
| Předmět: |
Cyclic plastic behaviour
Materials science Aluminium alloy Mechanical Engineering Crack tip opening displacement chemistry.chemical_element Paris' law Plasticity Industrial and Manufacturing Engineering Crack closure chemistry Mechanics of Materials Aluminium Modeling and Simulation visual_art Crack tip opening displacement (CTOD) Aluminio--Fatica visual_art.visual_art_medium Fatigue crack growth (FCG) General Materials Science Deformation (engineering) Composite material Plane stress |
| Zdroj: | Repositório Científico de Acesso Aberto de Portugal Repositório Científico de Acesso Aberto de Portugal (RCAAP) instacron:RCAAP RIUMA. Repositorio Institucional de la Universidad de Málaga instname |
| Popis: | In this work, fatigue crack growth (FCG) in the 2024-T351 aluminium alloy is studied using the plastic CTOD range, Δδp. Experimental tests were performed on 12 mm thick CT specimens in order to obtain FCG rate and in cylindrical specimens to obtain stress–strain loops. A numerical analysis replicated the experimental work in terms of material, geometry and loading conditions, but assuming pure plane strain state, in order to obtain Δδp. The material parameters were fitted using the experimental stress–strain loops. The experimental work showed an increase of FCG rate with the increase of stress ratio from R = 0.1 to R = 0.7 mm, which indicated the existence of the crack closure phenomenon. However, the analysis of the position of the first node behind the crack tip showed that there is no crack closure under plane strain state, while a maximum value of 36% was found for plane stress state. Therefore, the surfaces influence FCG rate even in 12 mm thick specimens. A nearly linear relation was found between da/dN and Δδp. The comparison with other aluminium alloys showed that there is a significant influence of material on da/dN-Δδp relation. The change from plane strain to plane stress state decreased FCG rate due to crack closure. Under plane strain state there is a minor influence of stress ratio in the range R = 0.1–0.7, also because there is no crack closure. Finally, a comparison was made between plastic CTOD and cumulative plastic strain at the crack tip. Well defined relations were found, showing that both parameters can be used to quantify crack tip deformation. The authors would like to acknowledge the financial support from Project PTDC/CTM-CTM/29101/2017 – POCI-01-0145-FEDER-029101 funded by FEDER funds through COMPETE2020 - Programa Operacional Competitividade e Internacionalizaç˜ao (POCI) and by national funds (PIDDAC) through FCT/MCTES. This research is also sponsored by FEDER funds through the program COMPETE – Programa Operacional Factores de Competitividade – and by national funds through FCT – Fundaçao ˜ para a Ciˆencia e a Tecnologia –, under the project UIDB/00285/2020, UIDB/00481/2020 and UIDP/00481/2020. Financial support from the Junta de Andalucia through grant reference UMA18-FEDERJA-250 of Programa Operativo FEDER and Subprograma Estatal de Movilidad, del Plan Estatal de I+D+i through grant reference CAS18/00251 is also greatly acknowledged. The authors would also like to acknowledge the funding for open access charge: Universidad de Málaga/CBUA. |
| Databáze: | OpenAIRE |
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