Comprehending the ductile behavior of slotted bolted connections

Structural steel special moment frames are designed to resist earthquakes with substantial inelastic energy dissipation. The ductile beam-to-column connections become more popular over these years by dissipating the earthquake input energy at beam ends. The paper provides a comprehensive study of a high-strength slotted bolted connection (SBC). Slotted holes instead of round holes are used for the connection such that frictional sliding could be developed. Experimentally, a standard bolt-weld connection as well as three similar slotted bolted connections were designed and tested. The load-carrying capacities, the ductile deformations, the energy dissipation capacities, and the hysteretic characteristics of the specimens were presented. The overall performance of the steel connections by replacing the circular holes with slotted holes is evaluated, and the design recommendations of the flange gusset plate with slotted holes are provided. Numerically, the nonlinear SBC behavior was simulated and calibrated against the experimental results. The SBC effectiveness as well as the parametrical influences have been presented in details. Results show that the friction slippage behaviors of the specimens with slotted holes provide better ductility, higher plastic deformation capacity, and increased load-resisting capacities near the ultimate strength.