Influence of the geometry on the fatigue performance of crenellated fuselage panels

Crenellation is a novel local engineering technique aimed at improving the fatigue performance of the airframe structures without increasing the weight. In this concept, a systematic thickness variation is applied to the fuselage skin to retard the fatigue crack growth. In order to achieve the best retardation effect, it is necessary optimize the crenellation geometry. As a result, a parameter study characterizing three independent geometric aspects of the crenellations was performed: the crenellation ratio c, the periodic length λ and a position parameter. The study was based on a FEA model validated by experiments. It is expected to give a sufficiently accurate prediction on fatigue life of different crenellation patterns. The obtained knowledge concerning the impact of those geometrical factors could provide guidance for future crenellation designs for industrial applications.