Prediction of stress intensity magnification factors of a semi-elliptical weld toe crack in load-carrying cruciform fillet-welded joints

• Main Author: Wai, Myo Htet
• Other Authors: Lie Seng Tjhen
• Format: Final Year Project
• Language: English
• Published: 2017
• Subjects: DRNTU::Engineering::Civil engineering
• Online Access: http://hdl.handle.net/10356/70834
• Institution: Nanyang Technological University

For steel structure, load-carrying filled-welded cruciform joint are widely used. However, if the cruciform joints need to use in the structure the fatigue life of the joints needed to be analysed so that the structure is safe. In this Final Year Project report, stress intensity magnification factors (Mk) of such configuration cruciform joint with semi-elliptical crack at the weld toe are calculated using 3-D finite element (FE) analyses. Mk values obtained for load-carrying cruciform joints are much larger than the corresponding values of non-load-carrying cruciform welded joints because of the presence of unpenetrated region in the welded joints. Thus, the new Mk equations for the load-carrying are proposed and built up using multiple regression analyses. The result obtained from the new equations are then validated using statistical analyses for the good fit of the equations. It is observed that the equation from British Standard 7910 (BS 7910) produces over conservative prediction on Mk values compare to newly proposed equations.