Fatigue life of a friction welded joint with a circular crack in the centre

✍ Scribed by A. Tjernberg

• Publisher: Elsevier Science
• Year: 2000
• Tongue: English
• Weight: 456 KB
• Volume: 7
• Category: Article
• ISSN: 1350-6307
• DOI: 10.1016/s1350-6307(99)00023-0

✦ Synopsis

This paper compares the calculated fatigue life with the tested life, for an embedded crack in the friction weld between two axially loaded rods. The initial crack is caused by lack of fusion in the centre of the friction weld. The radius for the initial circular crack is 5±6 mm. The stress intensity factors for the crack are calculated with the weight function method. It was found that a relatively high axial tensile residual stress must exist in the centre, to get the crack to grow suciently fast. An approximation for the residual stress distribution is used in the calculation. The calculation gives about 30% longer median lives than the fatigue tests. That might depend on uncertainties in material data and/or the fact that the tensile stress in the centre is higher than expected. The paper also shows that the integrals in the weight function method can be solved by a standard mathematics program.