A composite double-lap joint with staggered bolts: an experimental and analytical investigation

The objective of this study is to investigate the bolt load distribution in double-lap joints with five staggered bolts. The measured strain values near the bolts are used to establish the validity of the analytical predictions based on the concept of virtual work in conjunction with the complex potential theory. The total potential energy also includes the strain energy of the bolts based on a shear deformable beam theory. This method provides the contact stresses around the bolts holes, and thus the loads exerted by each bolt, while accounting for the interaction of bolts. The measured and predicted strain values are in agreement, verifying the accuracy of the predicted bolt loads. Damage and its growth are also examined by applying X-rays to the specimens prior to and after loading. The extent of the damage correlates to higher contact stresses.