Fatigue experiments and finite element analysis of bolted/bonded double lap joints

High-strength steel hybrid joints that combine adhesive and bolts have been studied both experimentally and numerically. The fatigue strength of the double lap joint has been experimentally measured under completely reversed cyclic loading. Finite element analysis was used to estimate the stress state at the contact interface of the lap joint. The fatigue strength of bonded and clamped interfaces which have previously been characterized using napkin ring specimens has been combined with the finite element results. The region of the double lap joint which showed fretting damage corresponded well with the region estimated to have significant damage based on the assessment. The resulting fatigue strength assessment was conservative with respect to the experimental results.