Static strength and load bearing behaviour of hybrid bonded bolted joints: experimental and numerical investigations

Hybrid joining techniques are increasingly coming into focus in the construction industry due to their numerous advantages. A hybrid joining technology for steel construction, the hybrid bonded bolted (HBB) joint, is manufactured by combining high-strength pre-stressed bolts with structural bonding. This article focuses on the influence of the adhesive's stiffness on the load-bearing and failure behaviour of hybrid bonded bolted joints. In addition, HBB joints with different granules in the adhesives as well as adhesive tapes are analysed. It is shown that the load-bearing capacity of the joint can be increased by up to 70% compared to preloaded bolted joints. The test results show that the adhesive's stiffness needs to exceed a threshold value to increase the load-bearing capacity. Adding granules with a high hardness to the adhesive layers has a significant advantage regarding the post-failure load-bearing behaviour. HBB joints only show a slight decrease of the load-bearing capacity (less than 10%) after reaching the maximum load. Compression tests on bonded steel plates investigate the correlation between preload force and indentation of the granules. Based on the experimental results, additional numerical investigations show how the geometric design of the hybrid joint can be optimized concerning the load-bearing behaviour.