Fatigue behaviour of full scale flat stiffened aeronautic panels

This paper concerns the experimental characterization of static and fatigue strength of a flat panel stiffened by bonded pad made of aluminum alloy. The panels were full scale and tested under both static and fatigue loads, applied by means of an in house designed and built multi-axial static and fatigue machine. The fatigue crack propagation life of the stiffened panel has been compared to that of a simple flat panel and to that of a flat panel with chemical milling pad-up, getting that the fatigue crack growth life can be significantly improved