Challenges on the elaboration of educational kits for the construction of rolled steel connections using 3D printing

Resumen

The visualization of the encounters between rolled steel pieces that concur in a connection is sometimes difficult to understand in the learning process of how to build this kind of structures. Previous experiences using structural models and kits have shown improvements on the understanding of the subject because students are able to reproduce in a practical way, using those physical models, the building solutions that they have learned theoretically. The limitations of these structures should be also taken into account. In which, in addition to the pieces preparation, it is needed to weld them in order to strengthen the connections. This allows highlighting the priority of some elements among others, the necessity of continuity of some of them according to the local solicitation, the order of the welding and the need for cuts in some pieces for their connection. This work pretends to analyze the advantages of the use of models done by 3D printing in the motivation of the students in the learning experience. There have been many difficulties in the planning, design and elaboration of the pieces to get a complete structural kit. To achieve a versatile model which allows reordering its pieces for reproducing different joints has required solving different problems. Starting with the choice of an accurate scale for the management, visualization and subsequent custody of the models in every case, as well as the selection of the most suitable profiles for the representation of multiple joints. On the other hand, the choice of the material, the thickness and the filling of the pieces, the same with the management of printing times and the difficulties in the balance of the pieces have required a redesign of the prototype in order to minimize material quantities, printing lengths, defective pieces... and to increase the performance in the elaboration of the proposed models. In the present research work, the difficulties encountered during the process of designing and elaborating an educational kit to support the learning of rolled steel connections are highlighted.