## 6 Conclusions
To establish the connection, the team considered the prequalified bolted flange plate (BFP) connection, referencing the AISC 358-16 [6] standard. The calculation and sizing analyses of the upper and lower plates of the skids, as well as their respective shear plate, were extracted from the specifications provided for the welded connection in the proposal. The analysis of the von Mises stress allowed us to determine that the elements enter the plastic range, specifically the wing and the flanges of the beam, posterior to the area where the plates welded to the flange are located. This can also be evidenced in the plastic deformation analysis, which provides the area where the core is plasticizing at 0.04 rad. Based on the results obtained, it is concluded that the columns filled with concrete allow the structural elements to be optimized, specifically in the sizing of the thickness of the tubular columns. Still, they do not generate a greater contribution to the type of connection with welded plates evaluated, since, due to the very shape of the connection, the development of the plastic hinges occurs after the welded plates. With the help of the analysis of the hysteretic curve in the different types of connections, it was obtained that all of them do not meet the bending resistance criterion at 0.04 rad, and are below 80% of the plastic moment. However, at 0.02 rad, the value of 80% of the probable moment is exceeded. Thus, the connections with welded plates, both in the flange and the web, are validated for an intermediate moment frame (IMF) type building, optimal for areas of moderate seismicity. The proposal analyzes the types of connections used in construction, which do not comply with AISC 358-16 regulations [6]. These connections would be used in intermediate moment frames (IMF). It has also been verified that these connections do not respond adequately to SMF frames, according to the protocol specified in the AISC 341-16 regulations [5]. Considering the current reality of the construction sector, metal connections must comply with strict regulations to guarantee structural safety during seismic events. Pre-qualified connections, such as those described in ANSI/AISC 358-16 [6], are essential for structures that must operate in the inelastic range and adequately dissipate energy. In Ecuador, many structures do not comply with these regulations due to the application of fillet welds instead of full penetration welds, which could compromise the rigidity and safety of the connections. If a connection is desired to be used in a special moment frame system, the best option would be the 3-A connection which has superior performance in terms of plastic moment and plastic deformation, and this suggests a greater capacity to dissipate energy and resist deformations under severe seismic loads. Although no connection completely meets the 0.04 rad criterion, connection 3-A offers the best overall performance, proving to be the most suitable for applications in SMF systems where more robust and resistant behavior is expected. D.F.C.-M. and I.S.V.-S.: review of the state of the art, analytical structural dynamic analysis of the frame, preparation of 3D models, analysis and calibration of the models for finite element analysis, and evaluation of results. F.P.M.-M.: analytical structural dynamic analysis of the frame, evaluation of results, and project management. P.B.T.-J. : analysis of information, analytical structural dynamic analysis of the frame, evaluation of results, and text review. E.V.-S.: preparation and writing of the manuscript, translation. All authors have read and agreed to the published version of the manuscript. The Salesian Polytechnic University, Cuenca, Ecuador, supported this research through the Master's Program in Mechanical Engineering, with mention in the Design of Metal Structures in Civil and Industrial Works, RPC-SO-24-No.540-2020. Not applicable. Informed Consent Statement: Informed consent was obtained from all subjects involved in the study.