Fatigue crack growth analysis in Al/Ti layered material in ambient and cryogenic conditions

The paper deals with the process of crack growth in a layered material made by explosive welding from AA2519 aluminum alloy and Ti6Al4V titanium alloy. The tests involved loading CT type specimens parallel to the weld surface so as to cause simultaneous fatigue crack growth in both layers. Independent optical measurement of the crack growth lengths enabled comparison of the crack growth behavior for both layers and relating them to the results of a crack growth analysis performed by the compliance method with the use of a COD extensometer and FEA crack length analysis. Tests of crack growth lengths by the compliance and FEA methods were also performed in a liquid nitrogen which made it possible to compare the crack growth behavior in ambient temperature and cryogenic temperature.