Design theory and numerical analysis of earthquake-resilient joint with slotted bolted connection

Bolted connections are preferred in prefabricated steel structures with the advantages of quality control and convenient construction. An innovative type of earthquake-resilient joint with slotted bolted connection (ERJ-SBC) is proposed to achieve damage control and improve the ductile behavior of steel structures. The bending moment is assumed to be mainly transferred by the flange segments of SBC while the shear force is carried by the web segments. The energy dissipation capacity of ERJ-SBC is provided by the initial frictional sliding and inelastic axial deformation of SBC under larger displacement. Design theory is proposed to ensure that inelastic deformation is concentrated in SBC while other structural members remain elastic. The influences of the length of slotted holes, bolt pretension, friction coefficient, and the thickness and width of the sliding plate are investigated through the numerical analysis of 44 FE examples. The calculation of the critical length of slotted holes for the ductile rotation behavior of ERJ-SBC is derived and verified. Results demonstrate that the mechanism of bolted connection shifts from friction resistance to bearing resistance when bolts collide with slotted holes, and the friction slippage behavior with slotted holes benefits the hysteresis behavior, deformation capacity, and rotation behavior. The proposed calculation methods for the mechanical behavior of ERJ-SBC could achieve good accuracy with simulation results. A reasonably well-designed ERJ-SBC could have good bearing capacity and rotation behavior, and it could also achieve damage control.