The paper gives the results of test investigations on fatigue and damage tolerance characteristics of panels that represent typical longitudinal lap joints of fuselage skin made of 2024-T3A alloy. During the tests multiple site cracks (MSD) formed in these joints, and their linkage led to the fracture of panels. The results of these tests had been analyzed and corrective factors were derived for the stress intensity factors (SIF). Final corrective factors for SIF take into account the following effects: - influence of open hole/holes; - influence of riveting/filled hole; - the load transfer through the rivet; - bending effects; In addition, the following characteristics were defined: - durability of panels (before visible crack initiation); - crack growth characteristics (time, rates) till the fracture of panels; - residual strength criteria for the panel described Results of the tests conducted are useful while estimation/calculation of inspection intervals beginning and periods, and limit service life (LOV) of longitudinal skin joints of fuselage structure while design stage and while operation.
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