Connection Behavior Analysis of Drilled Reduced Beam Flange and Reinforced Concrete Column

Composite special moment frames represent a novel type of special moment frames (SMFs) where a combination of concrete columns and steel beams is used. This paper evaluates the modeling of composite special moment frames and the behavior of the steel beam-concrete column connection. Due to the focus on hinge formation, the behavior of the connection with a hole drilled on the beam flange was analyzed. Numerical simulations were carried out in ABAQUS. The beam-column connection was subjected to one-five rows of holes. It was observed that the beam-column connection with three rows of holes had the optimal hinge formation behavior, stress distribution, and load. The connection with five rows of holes showed plastic strains in the first four rows, while the fifth row had no plastic strain. This suggests an increased drilling space since the fifth hole row did not contribute to the improvement of stress distribution uniformity. It was numerically found that the bending moment change varied from 8% to 46%; the model with three rows of holes had the lowest bending moment change, whereas the model with a single hole row showed the highest change in the bending moment. Moreover, energy absorption changed by 4-20%.