Naslov
Fatigue Life Prediction for Tension Panels with Multiple Propagating Cracks

Autori
Božić, Željko ; Semenski, Damir ; Wolf, Hinko

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, sažetak, znanstveni

Izvornik
Abstract Book of International Conference on Fatigue Damage of Structural Materials VII / Martin R. Bache - Hyannis (MA) : Elsevier, 2008, P3.7-P3.8

Skup
International Conference on Fatigue Damage of Structural Materials VII

Mjesto i datum
Hyannis (MA), Sjedinjene Američke Države, 14.09.2008. - 19.09.2008

Vrsta sudjelovanja
Poster

Vrsta recenzije
Međunarodna recenzija

Ključne riječi
fatigue life prediction; crack propagation; multiple cracks

Sažetak
Fatigue crack growth tests with constant stress range and frequency were carried out for a plate with a single centre crack, P1, and a plate with three collinear cracks, P3, (see Fig.1). The applied average stress range and loading frequency were 80 MPa and 5 Hz, respectively, where the specimens' material was a mild structural steel. Based on experimental a-N data obtained for the two specimens, (see Fig.2), crack growth rates were calculated, (see Fig.3), and Paris' equation constants were estimated. It was observed in the experiment that in case of specimen P3 the crack tips propagated at different crack propagation rate, where the tip 1 showed the highest propagating rate. An interactive crack propagation simulation procedure for multiple propagating crack tips was introduced, using a FEM analysis to calculate stress intensity factors, KI, and numerical integration of Paris' equation. Generally, any propagating crack tip can be taken in the simulation procedure as a reference to which assumed initial increments are related. For the specimen with three cracks the simulation has been carried out assuming two different referent crack tips that yielded the same results, showing that the procedure takes interaction of propagating crack tips properly. Initial crack growth rate values for the two specimens fall on a straight line in the logarithmic scale. However, for the second part of the specimens' crack propagation lives (approximately 30% of the ligament is cut), the rate increased significantly, particularly that of P1 specimen, (see Fig.3). This phenomenon was taken into account in the simulation procedure by using modified Paris' equation constants for the higher crack growth rate values. A good agreement of simulation and experimental results was achieved, (see Fig.2).

Izvorni jezik
Engleski

Znanstvena područja
Grafička tehnologija, Strojarstvo, Prehrambena tehnologija

POVEZANOST RADA