Numerical and analytical investigation of reduced beam section with and with yielding damper and their comparison

Abstract

Connections are one of the sensitive points in structures, including steel structures, which have a significant impact on the seismic behavior of the structure. One type of connection used in steel structures is the Reduced Beam Section (RBS), which reduces the moment strength of the beam near the column, resulting in less moment being transferred to the column at the final moment. In this research, 36 numerical analyses were performed using ABAQUS to investigate two cases. In the first case, a connection with a beam with a hole in the flange area was examined, with the area of the flange holes and the axial force of the column as variables. In the second case, a yield ring was used in the flange area of the beam, with the radius of the yield ring as the variable in six cases. Analytical formulas for calculating the maximum strength moment of the beam, as well as equations for analysis in the linear region, were presented. One design requirement of the yielding damper is to yield earlier than other members, and an equation was presented to ensure that yielding occurs first in the yielding loop. After performing the numerical analysis, it was observed that if the area of the flange holes is half of the area of the beam flanges, a significant decrease in strength does not occur with an increase in axial force up to a certain extent. One of the primary advantages of adding a yielding damper to the beam is the ability to adjust the maximum moment transferred to the column by changing the final moment of the beam.