Numerical investigation of the new steel connection using short stub column

There is little evidence of the formation of plastic zones in damagd structures in diffrent types of earthquakes. Most of the conducted studies have focused on creating a plastic hinge in a part of the beam making irreparable damage to the beam.  If the plastic joint in the beam does not occur, a force will be created which is more than the plastic moment of the beam and will be transferred to the connection and finally to the column. This will either cause the brittle failure of the connection or damage to the panel zone of the column. Therefore, in this research, four connections with new geometry have been proposed aimed at reducing damage in beams and columns and creating the possibility of replacing damaged parts. In general, the presented connections are suggested by replacement of an H or I-shaped cross section along with or replacing of an end-plate, as a short stub column. In this reserch, first, a finite element model of the end-plate connection, which is a combination of welding and screwing subjected to cyclic loading was selected. Then, after the validation of Abaqus software, a study was carried out on the proposed connections. The results indicate that the stub region, with its nonlinear behavior, creates a controlled limited joint with extraordinary ductility. Yielding in the stub causes its fusion behavior and prevents damage to beams and columns. It also significantly reduces the plastic stress and strain in the panel zone of the column.