Naslov
Modelling of overload effects on fatigue crack initiation in case of carbon steel

Autori
Mlikota, Marijo ; Schmauder, Siegfried ; Božić, Željko ; Hummel, Martin

Izvornik
Fatigue & Fracture of Engineering Materials & Structures (8756-758X) 40 (2017), 8; 1182-1190

Vrsta, podvrsta i kategorija rada
Radovi u časopisima, članak, znanstveni

Ključne riječi
crack initiation ; fatigue ; finite element modelling ; overload

Sažetak
This paper deals with the modelling of short crack initiation within a microstructure of medium carbon steel under fatigue loading, as well as with the influence of overload on the crack initiation period. Studies on the long crack growth show that the overload introduces first an increase in the crack growth rate that is then followed with a decrease, a so-called retardation. A micro-model containing the microstructure of the material is analysed using the finite element method in combination with a model for crack development – the assessment of number of cycles needed for crack initiation was based on the Tanaka–Mura equation. The analysis brings in a correlation between the crack growth rate and the crack length together with the effects of the overload on the crack growth rate. The overload is found to accelerate the short crack growth ; however, the following retardation could not be captured due to the inability of the model to produce residual stresses, which are considered to be the main cause of the retardation effect.

Izvorni jezik
Engleski

Znanstvena područja
Strojarstvo

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