Experimental determination of accurate fatigue crack growth data in Tailored Welded Blanks

Joining of Tailored Welded Blanks (TWB) with Friction Stir Welding (FSW) is very attractive for future aircraft applications. This article provides the main findings of extensive studies of fatigue crack propagation in FSW-TWB made of AlMgSc alloy. The measurement of actual mechanical test conditions in combination with finite element simulations allows overcoming inherent drawbacks of conventional single edge notch tension (SENT) specimens. Residual stresses as result of the FSW process are measured via the cut-compliance-method. It is shown, that in case of FSW-TWB only the consideration of actual test conditions and residual stresses yields accurate fatigue crack propagation data.