The effect of fiber length and structure on joint strength in bonded joints with fiber-reinforced composite adhesive

Today, composite materials are frequently used as materials in engineering due to their light weight and strength. Studies on the use of composite materials and the adhesively bonded joints used to bond these materials are of importance. In general, studies on the bonding method with adhesives are concerned with the strength of the joint. In this study, fiber fabric was reinforced to the bonding area in order to increase the strength of the bonding connections used in the aviation and automotive fields. DP460 structural adhesive as adhesive and AA2024-T3 aluminum alloy used in aviation field as bonded material were used to produce a single-lap joint bonded with adhesive. In addition, carbon fiber, glass fiber and aramid fiber fabric were used as reinforcing elements in the adhesive zone. Furthermore, to examine the effects of fiber fabric length in the overlap area at joint-failure load, four different length fiber fabric such as 100%, 80%, 40% and 20% of the overlap length were added. As a result, when the experimental failure loads were examined, the composite adhesive obtained by adding fibrous fabric has been found to increase the load failure of the joint between about 16% and 90%. However, increase rate in the failure load changes depending on the length fiber fabric and the type of fiber fabric. Moreover, in the geometries of single-lap joints produced in this study, the best fiber fabric type, in terms of the failure load of the joint, was carbon fiber fabric.