Issue 36

M. Arsic et alii, Frattura ed Integrità Strutturale, 36 (2016) 27-35; DOI: 10.3221/IGF-ESIS.36.03 35 Figure 11 : Curve da/dN –ΔK. C ONCLUSION resented research and established mathematical relationship between critical crack length and fatigue strength offer great possibilities for analysis of fatigue behavior of welded joints made from structural steel S355J2+N on the supporting structures of building machines, dredgers, elevators, bridges, supporting structure in power plants, petrochemical and oil industry. In addition to this, presented results enable analysis of welding procedure, significant welding parameters and welding consumable material quality aimed to minimize negative effects of variable load to welded joint, i.e. to implement convenient structure. Established mathematical relationship between critical crack length and fatigue strength of K-grooved butt welds have general character for structural steels, because it enables evaluation of critical crack length for all welded joints with surface imperfection of undercut type and welded joints with incomplete root penetration. A CKNOWLEDGEMENT e would like to thank to Ministry of Education, Science and Technological Development of Republic of Serbia for the financial support of research within the project TR 35006 and TR 35040. R EFERENCES [1] Arsić, M., Corelation between weldment fatigue strength and fatigue threshold (in Serbian), doctoral thesis, University of Pristina, (1995). [2] Radon, J.C., Study of Surface Fatigue Cracks, Structural Integrity and Life, 6 (2006) 97-100. [3] Manjgo, M., Sedmak, A., Grujić, B., Fracture and fatigue behaviour of NIOMOL 490K welded joint, Structural Integrity and Life, 8 (2008) 149-158. [4] Gliha, V., Burzić, Z., Vuherer, T., Some Factors Affecting Fatigue Resistance of Welds, Structural Integrity and Life, 10 (2010) 239-244. [5] Milović, Lj., Bulatović, S., Radaković, Z., Aleksić, V., Sedmak, S., Marković, S., Manjgo, M., Assessment of the Behaviour of Fatigue Loaded HSLA Welded Steel Joint by Applying Fracture Mechanics Parameters, Structural Integrity and Life, 12 (2012) 175-179. P W