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