Analisi del comportamento statico e a fatica di giunzioni stampate in materiale composito

The paper presents the results of an experimental investigation on the static and fatigue behavior of co-cured stepped lap composite joints. The results of a careful damage evolution analysis identify in the delamination at the layer's interface the mechanism controlling the failure of the joints and they allow to justify the average increase in the joint strength, both in static and fatigue tests, as the layer overlap increases. The presence of the connection induces however a significant reduction, up the 45%, in the laminate static strength and a strong sensitivity to the fatigue damage, with a joint fatigue strength at 2 million cycles ranging from of 25% to 48% of its static strength.