An inverse method for evaluating weld residual stresses via fatigue crack growth test data

✍ Scribed by Rui Bao; Xiang Zhang

• Book ID: 103828891
• Publisher: Elsevier Science
• Year: 2010
• Tongue: English
• Weight: 992 KB
• Volume: 77
• Category: Article
• ISSN: 0013-7944
• DOI: 10.1016/j.engfracmech.2010.08.010

✦ Synopsis

This paper presents an inverse method for calculating the thermal residual stresses in welded specimens via measured fatigue crack growth rates. Firstly, fracture-mechanics superposition law has been used to extract the stress intensity factor due to residual stress contribution from measured crack growth rate. Secondly, a so-called B matrix has been established by performing finite element analysis. Residual stress distribution is then determined by solving linear algebraic equations relating the B matrix and residual stress intensity factors obtained from crack growth test data. The inverse method has been validated by a well-established residual stress distribution and corresponding stress intensity factor, and then applied to an M(T) sample in 2024-T3 alloy with a longitudinal weld. Agreement with the measured residual stresses is reasonably good and reasons for certain differences between the calculated and measured are discussed.