Seismic performance of beam to column connections with T-shaped slit dampers

摘要

In this paper, a new steel yielding damper in the beam-to-column connections relying on the combination of slit damper and T-stub called T-SSD is proposed, with an aim to increase energy dissipation capacity and stiffness as well as to reduce seismic damage on the structure. Different patterns of connections are considered in the analysis. Nonlinear finite element method is employed to deal with realistic modeling of the specimens and to capture all the main seismic behavioral aspects including the strength, the stiffness, the energy dissipation, ductility, von-Mises stress and equivalent plastic strain distributions of models. A parametric study on the geometry of slit dampers is also performed to determine the best geometrical configurations in terms of mechanical performance. According to the results, the models with T-SSD systems possess satisfactory hysteretic performances. Yielding and local buckling of the T-SSDs under seismic events serve as the primary source of energy dissipation, while the other structural components remain essentially elastic. Strength and energy dissipation capacities were essentially improved by changing the slits configuration. The T-SSD connections can supply the highest initial stiffness, bearing capacity, ductility, and energy dissipation increases by 63%, 94%, 80%, and 35%, respectively, with respect to the T-stub connection. The presence of shear tab in connections could typically result in increased initial stiffness by as much as 25% in comparison with counterpart without shear tab. Theoretical equations estimate the initial stiffness and bearing capacity of the connections 15% more than and 50% less than those of the numerical results, respectively.