Seismic performance evaluation of a replaceable steel beam with slotted bolted connections

Abstract

Serious losses caused by earthquakes have led to significant demand for replaceable devices with strong energy-consuming capacity in Earthquake Resilient Structures. Slotted bolted connections (SBCs) could dissipate seismic energy through friction-slip. This paper applies SBCs to replaceable steel beams in the proposed hybrid frame structure with energy dissipation frames (HF-EDFs) to improve seismic performance and recoverability. The design concept and the energy dissipation mechanism of the replaceable steel beam with slotted bolted connections are described in detail. The corresponding formulas are derived to realize that friction-slip behavior occurs before the steel beam yields. Totally six steel beam specimens are designed for a pseudo-static experiment to evaluate the seismic performance by varying the type of connections and the size of the SBC slotted holes. Moreover, the effects of the SBCs arrangement and slotted holes size are further studied by Finite Element (FE) analysis. Both the test and FE results indicate that friction-slip behavior occurred in the steel beams with SBCs as intended, and all the specimens failed in a typical shear type. The specimens with end-plate connections are superior in energy-consuming capacity compared to those with T-shape connections. Meanwhile, the deformation and energy consumption capacity were notably increased as the size of the slotted holes increased. In addition, the arrangement of the double-sided SBCs can improve the energy consumption by 97.5% compared to that of the single-sided before yielding. The research findings are expected to provide reference for the design and applications of the replaceable steel beams with SBCs.