Load transfer in hybrid (bonded/bolted) composite single-lap joints

The load transfer in hybrid (bolted/bonded) joints is complicated due to the difference in stiffness of the alternative load paths. The load distribution in hybrid composite single-lap joints has been predicted through use of a three-dimensional finite element model including the effects of bolt-hole contact and non-linear material behaviour. The effect of relevant joint design parameters on the load transferred by the bolt have been investigated through a finite element parameter study. Joint configurations where hybrid joining can provide improved structural performance in comparison to adhesive bonding have been identified. Experiments were performed to measure the distribution of load in a hybrid joint. A joint equipped with an instrumented bolt was used to measure the load transfer in the joint. The measured bolt load values were compared to predictions from the finite element model and the results were found to be in good agreement.