Naslov
Analytical and Numerical Investigation of Crack Opening in Strain - Hardening Material

Autori
Pustaić, Dragan ; Lovrenić, Martina

Vrsta, podvrsta i kategorija rada
Radovi u zbornicima skupova, cjeloviti rad (in extenso), znanstveni

Izvornik
Proceedings of the 5th International Congress of Croatian Society of Mechanics / Matejiček, Franjo - Zagreb : Hrvatsko društvo za mehaniku (HDM), 2006, 141-142

Skup
The 5th International Congress of Croatian Society of Mechanics

Mjesto i datum
Trogir, Hrvatska, 21.09.2006. - 23.09.2006

Vrsta sudjelovanja
Predavanje

Vrsta recenzije
Međunarodna recenzija

Ključne riječi
Isotropic strain-hardening material; Magnitude of plastic zone; Crack tip opening displacement (CTOD); Crack centre opening displacement (CCOD); J-integral

Sažetak
An evolution of appropriate algorythm for determining the parameters of elastic-plastic fracture mechanics by analytical methods is a main goal of this paper. In this place it is firstly opined on crack's behaviour in a ductile fracture conditions and in the transitional states from brittle to ductile fracture. Our aim is understanding of crack behavior in an isotropicaly strain-hardening material. These investigations are being continued on the previous investigations of fracture mechanics parameters in which the authors (D. Pustaić and B. Štok) had kept an assumption about constant cohesive stresses within a plastic zone around a crack tip, i.e. an assumption on elastic perfectly plastic material's model of solid body, respectively. Because it is a very rudely approximation, in the present investigations we have assumed a non-linear distribution of cohesive stresses within a yielded zone around crack tip. For example, M. Wnuk and J. Legat, and W. Guo, too, have introduced the similar assumptions in the their papers. A difficulty is in fact that neither a distribution law of those stresses nor a magnitude of cohesive zone rp are not known. Therefore, we have used a Finite Element Method (FEM) and commercial code ABAQUS in order to obtain a distribution law of the cohesive stresses. The numerical calculations have been carried out for the several different values of strain hardening exponent n in the Ramberg-Osgood's equation and in a case of a value of parameter α = 1. In that way obtained cohesive stresses distribution we approximated by some known function, for example by exponential function, either by logarithmic function or by hyperbola. Further analysis of the elastic-plastic fracture mechanics parameters was carried out by the analytical methods using some of well-known mechanisms (models) of plastic yielding.

Izvorni jezik
Engleski

Znanstvena područja
Strojarstvo

Napomena
Rad je usmeno izložen na spomenutom kongresu, u Power Point Presentation. Jedan od autora, prof. dr. sc. Dragan Pustaić predsjedavao je jednom sekcijom i pripadao je timu međunarodnih recenzenata (International Review Committee) koji su recenzirali sve radove za ovaj međunarodni kongres.

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