Mechanical analysis and design of adhesive bonded joints

The mechanical behaviour of the adhesively bonded joints depends on many parameters such as the geometrical features of the joint and the features of materials generating it. This dependence complicates the prediction of the overall mechanical behaviour of the joint. In order to understand the mechanical behaviour of adhesively bonded joints, many studies have been carried out and different models have been proposed.In this thesis, it has been analyzed the mechanical behaviour under axial tensile loading of the single lap joints bonded by using two different adhesives that one is stiff and the other is flexible having different overlap lengths and different taper angles. The study has been carried out both experimentally and numerically. The bulk tensile specimens of adhesives used in the study have been initially prepared and then the stress-strain behaviour of the adhesives has been determined.With the aim of evaluating the performances of the used adhesives, it has been basically realized experiments at two different overlap distances. Additionally, the effect on the joint strength of merely taper angle has been endeavoured to identify, such that the specimens having 6 different taper angles has been jointed by being invented the overlap distances achieving to fix total adherence area and the obtained specimens also have been subjected to the strain experiment. Taking into consideration the stress-strain behaviour of the adhesives and the bonded material at the single lap joints bonded by using Neoxil CE92 N8 and SikaForce 7710, the stress analysis has been accomplished by the linear finite elements method. The experimental results have been compared with the obtained results by finite elements method and a good agreement has been observed.Consequently, the thesis has been finalized with the following novel emergent results: Although Neoxil CE92 N8 has more strength than SikaForce 7710, the joints bonded by SikaForce 7710 exhibits a good performance as well as the ones bonded by Neoxil CE92 N8 as increasing the overlap distance and changing the taper angle and even the performance of SikaForce 7710 may overcome that of the other according to the amount of the increasing or changing.Keywords: Adhesive joints, taper angle, overlap length, linear finite elements method, axial tensile loading.