Investigating clamping force variations in Al2024-T3 interference fitted bolted joints under static and cyclic loading

Abstract

In this paper the variation of bolt clamping force in interference fitted-bolt clamped aluminum 2024-T3 specimens in double shear lap joints have been investigated under static and cyclic loads. In experimental part of the study, static or cyclic longitudinal remote loads have been applied to the joint and the variations of bolt clamping forces were measured in the tests. Finite element analysis was also performed and the results were compared with the results of statically loaded experimental tests. The results showed an initial reduction of the clamping force followed by an increase for bigger longitudinal static load. During cyclic loading in experimental tests, bolt clamping force reduction was observed in the first 1000 cycles, especially for joints with higher size of the interference fit. This reduction was due to the scrape of the protruded region around the hole, left from bolt interference fitting, on the exit plane of the main part.