Naslov
Fracture Behaviour of High-Ductile CCT Specimen Under Elastic-Plastic Conditions

Autori
Matejiček, Franjo ; Kozak, Dražan ; Konjatić, Pejo

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

Izvornik
Extended Abstracts and Proceedings (CD-ROM Edition)of the 4th International Congress of Croatian Society of Mechanics / Matejiček, Franjo - Zagreb : Hrvatsko društvo za mehaniku (HDM), 2003, 601-608

Skup
4th International Congress of Croatian Society of Mechanics

Mjesto i datum
Bizovac, Hrvatska, 18.09.2003. - 20.09.2003

Vrsta sudjelovanja
Predavanje

Vrsta recenzije
Međunarodna recenzija

Ključne riječi
CCT Specimen; J-integral; crack growth; J-R curve; crack driving force; FE analysis

Sažetak
In assessing the integrity of structures containing cracks, it is important to quantify the relevant crack-driving force, so that its load carrying capacity can be predicted. For ductile materials permitting large-scale plasticity near the crack tip, this crack-driving force is frequently described as contour J-integral, which is one appropriate elastic-plastic fracture mechanics (EPFM) parameter (in absence of constraint effects) of low-strength and high-toughness materials. If there is excessive plasticity or significant crack growth, fracture toughness may depend on the size and geometry of the test specimen. Therefore, methodology for J-integral and crack length estimation of a CCT specimen made of high ductile stainless steel is presented in this paper. Estimation is conducted using results gained by experiments and it was confirmed using finite element analysis (FEA). Research was conducted on specimens made of stainless steel X 5 CrNi 18 10, with yielding strength of Rp0, 2=250 MPa and stress of 620 MPa by elongation of about 16%. First series of tests were conducted on specimens prepared for classic tension test to determine real characteristics of material including &#963 ; -&#949 ; diagram, and after on standard CCT specimens with 2a/W = 10/30 = 0, 3. During testing, behind the force F, three characteristic displacements were measured: load line displacement (LLD), crack mouth opening displacement (CMOD) and crack tip opening displacement CTOD (&#948 ; 5). Single specimen method with loading-unloading compliance technique is used to determine compliance of material and hereafter crack extension &#916 ; a. It is often in engineering practice that only J0, 2BL in crack resistance curve J-&#916 ; a could be determined corresponding to the fracture resistance at 0, 2 mm of ductile crack growth. J-integral for CCT specimen has been calculated measuring area under curve in F-LLD diagram. A three-dimensional final element model of CCT specimen was prepared for finite element analysis in Ansys code. Finite element simulations show very good agreement between experimental and numerical results and it can be applied to draw crack driving force.

Izvorni jezik
Engleski

Znanstvena područja
Strojarstvo

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