Improving the fatigue life of aeronautical single-lap bolted joints thanks to the hybrid (bolted/bonded) joining technology

It has been experimentally shown [1-5] the possibility to obtain with hybrid (bolted/bonded) joining technology higher static failure load and a longer fatigue life than the corresponding bolted or bonded joints by using a suitable adhesive. This paper aims at comprehensively showing, by both a simplified analytical approach and an accurate three-dimensional finite element analysis that the application of hybrid (bolted/bonded) joining technology instead of the classical bolted technology allows for a possible improvement of fatigue life. A simplified theoretical analysis is presented to understand the mechanical behaviour of such joints and to provide possible elastic mechanical properties of a suitable adhesive. Then, an accurate three-dimensional Finite Element model is developed to demonstrate the possible benefit on fatigue life