Hybrid Adhesive Joints

Adhesively bonded joints are increasingly being used in aerospace and automotive industries. The use of adhesive bonding rather than mechanical fasteners offers the potential for reduced weight and cost. However, there are still a number of issues that need to be solved before this technique is fully trusted by the industry. Due to the polymeric nature of the adhesive, the joint resistance to harsh environments and its durability must be taken into account. Another point is the fact that the stress distribution is concentrated at the ends of the overlap giving rise to premature failures, especially with composites. However, when used in combination with traditional methods of joining such as bolts, rivets or spot welds, part of the problem can be solved. That is why adhesively bonded joints with different methods of joining are being considered. The idea is to gather the advantages of the different techniques leaving out their problems. Some of the advantages of hybrid jointsare a higher static and fatigue strength and a higher stiffness with respect to simplejoints, a two-stage cracking process before the final failure and improved durability.They also offer the technological advantage of keeping parts in place while the adhesiveis curing. Another possibility to increase the joint strength of simple adhesive joints is touse more than one adhesive along the overlap. All these joints are treated here: weld adhesive, rivet adhesive, clinch adhesive, bolt adhesive, and adhesive adhesive.A section dedicated to threadlocking and interference-fit adhesive joints is alsoincluded. All sections are treated from a scientific point of view with modelling issuessupported by simple coupons testing and a technological point of view where the idea isto present more applied results with practical cases.