Analysis of the Effects of Interference and Sealant on Riveted Lap Joints

Abstract

Much of the fatigue damage in aircraft structures can be linked to the stress concentration arising at the rivet/skin interface in fuselage lap joints. Fatigue damage can degrade the strength of the structure and reduce structural integrity. Elastomeric adhesives and sealants are applied to the lap joints before riveting to prevent entry of moisture, thus, preventing corrosion. The effect of the sealant on the residual stress state resulting from the rivet interference and subsequent load transfer has not been investigated. A three-dimensional finite element model of the riveting process is simulated to determine the effects of interference and sealant on the induced stresses. Both implicit and explicit finite element techniques are utilized to model the process. The finite element simulation is validated initially for both techniques with experiment. The analysis with sealant shows an increase in the residual hoop stress for the majority of the cases in comparison to the results without sealant.