Non-Linear Behavior of New (FSFN) Moment Resisting Connections in Comparison to the Existing KBB Connections in Steel Frames

After Northridge (1994) and Kobe (1995) earthquakes, several studies have been conducted to improve the seismic performance of steel structures. In this investigation, new steel moment-resisting connections (FSFN) developed by the authors, were studied by the non-linear numerical analysis. These connections were single-sided beam-to-column assemblies that are representative of exterior beam-to-column connections. Seismic performance of FSFN connections in comparison to the W-series of existing KBB connections under standard and near fault load history based on AISC 341 and FEMA 355D were also studied. For this purpose, 32 analytical modeled specimens were evaluated and the results were compared. Results showed that FSFN bracket connection has a seismic performance similar to KBB connection and it is an appropriate connection for the special moment resisting frames both in far and near fault zones.  More so, these connections do not have patent and due to their dimensions which are smaller than the Kaiser brackets, they can supported deeper beams up to 100 cm.  Therefore, it can be considered as an appropriate alternative for the Kaiser patented connections. This paper is to present the analytical modeling, non-linear behavior and the results of the comparison studies in detail including obtained conclusions.