Processo di giunzione fra materiali dissimili tramite modelling ad elementi finiti (FEM) accoppiato a tecnologia di additive layer manufacturing (ALM) (o 3D printing) della zona di giunzione = Joining process between dissimilar materials via FEM paired with the additive layer manufacturing of the bondline.

In this master thesis, a new method for SL joints improvement is proposed. It has been carried out a study of the behaviour of the SL adhesive joints when the surface of the adherends is modified by placing a certain geometry on them. Moreover, it has been studied the possibility of benefiting from the additive manufacturing processes in order to fabricate these geometries, since this technology provides limitless possibilities when it comes to geometry generation. Research on SL joint improvement reveals some studies that focus on the surface modification to improve the strength of the joint. These studies may be separated in two groups: those who propose a mechanical modification of the surface, and those who use additive layer manufacturing to assembly both components together. In one hand, studies that propose mechanical modifications consist in a very simple geometry and does not let space for further improvements or modifications on them; since the geometries are performed through mechanical deformations of the current surface of the components, the geometries that may be generated are limited with few variations. On the other hand, the studies that make use of ALM processes does not focus on the geometry itself, they rather focus on the combination of both materials involved in order to build an unique component, obtaining enhanced properties. The objective of this master thesis is then to improve the performance of the SL joints while benefiting from both groups, by providing a set of defined geometries that may be fabricated through ALM and study their influence in the minimization of stress concentrations. In addition, besides the strength improvement this master thesis is also aimed to be applied to SL joints between two dissimilar materials, that may impose either adhesion problems and stress concentrations due to the difference in the mechanical properties of the adherends. Since SL joints may be subjected to different types of forces, a different study for each of those is necessary. In this master thesis, compressive forces on a SL joint is taken as the case of study for its performance improvement. In addition, single lap offset compression test contour conditions are considered during the experimental and simulation analyses. Moreover, research on SL joints reveals stress peaks in the edges of the bondlength, letting know where does the geometry have to reinforce to a greater degree. The stress diagram obtained from analytic studies of the SL offset compression test are taken into account during the designing process. Finally, once the prototypes have been fabricated, experimental tests were carried out simultaneously to simulations through finite elements for each of the models developed. Results obtained were then compared in terms of fabrication cost, rigidity, contact surface, material continuity and complexity.