Weld root crack propagation under mixed mode I and III cyclic loading

✍ Scribed by In-Tae Kim

• Publisher: Elsevier Science
• Year: 2005
• Tongue: English
• Weight: 614 KB
• Volume: 72
• Category: Article
• ISSN: 0013-7944
• DOI: 10.1016/j.engfracmech.2004.04.007

✦ Synopsis

This study examined fatigue propagation behaviour and fatigue life of weld root cracks under mixed mode I and III loading. Fatigue tests were performed on butt-welded joints with a continuous lack-of-penetration (LOP) inclined at angles of 0°, 15°, 30°or 45°to the normal direction of the uniaxial cyclic load. Branch and/or co-planar crack propagation was observed, depending on the initial mode I stress intensity factor (SIF) range. Co-planar crack propagation predominated when the SIF range was large. The fatigue crack propagation mode affected fatigue life; the life of branch crack propagation was longer than that of co-planar crack propagation. Using an initial equivalent SIF range based on a maximum strain energy release rate criterion, the results obtained from the 0°, 15°, 30°, and 45°specimens indicated almost the same fatigue lives, despite the different inclination angles.