Naslov
Modeling of fatigue microfracture in porous sintered steel by Phase-Field method

Autori
Tomić, Z. ; Jarak, T. ; Lesičar, T. ; Gubeljak, N. ; Tonković, Z.

Kolaboracija
Multiscale Numerical Modelling and Experimental Investigation of Aging Processes in Sintered Structural Components” (MultiSintAge, PZS-1 2019-02-4177).

Izvornik
Materials (1996-1944) 16 (2023), 11; 41-74

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

Ključne riječi
sintered steel, microcracks, fatigue, phase-field method, porosity

Sažetak
Porosity in sintered materials negatively affects its fatigue properties. In investigating its influence, the application of numerical simulations reduces experimental testing, but they are computation-ally very expensive. In this work, the application of a relatively simple numerical Phase Field (PF) model for fatigue fracture is proposed for the estimation of fatigue life of sintered steels by the analysis of microcrack evolution. The model for brittle fracture and a new cycle skipping algorithm are used to reduce computational costs. A multiphase sintered steel, consisting of bainite and fer-rite, is examined. Detailed finite element models of microstructure are generated from high-resolution metallography images. Microstructural elastic material parameters are obtained using instrumented indentation, while fracture model parameters are estimated from experimental S-N curves. Numerical results for monotonous and fatigue fracture obtained are compared with data from experimental measurements. The proposed methodology is able to capture some im-portant fracture phenomena in the considered material, such as the initiation of first damage in microstructure, the forming of larger cracks at the macroscopic level, and the total life in the high cycle fatigue regime. However, due to the adopted simplifications, to model is not suitable for predicting accurate realistic crack patterns of microcracks.

Izvorni jezik
Engleski

Znanstvena područja
Strojarstvo

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