Experimental Study on a Single-Sided Column–Tree Connection with a Replaceable Buckling-Restrained Cover Plate at a Bottom Flange

Abstract

This paper presents the study of a single-sided column–tree connection with a replaceable buckling-restrained cover plate (BRCP) at a bottom flange to achieve rapid postearthquake repair for connections in the presence of concrete slabs. During major earthquakes, the bottom flange core plate of the BRCP yields and dissipates energy, and the connection rotates around the center of the top flange connection plate. The slip and yield moments of the proposed connection were theoretically calculated, and the design principle was proposed. Quasi-static loading tests were performed on four specimens. Moreover, the hysteresis behavior, failure modes, force–deformation hysteresis curves, force–deformation backbone curves, strain responses, energy dissipation capacity, and neutral axis position were obtained. Additionally, the influence of restrained forms, unbonded material, and neutral axis position on the hysteresis performance were analyzed. The results show that the two-piece restraint plate leads to extreme local bending of the core plate, the unbonded material on the restraint plate has little effect on the seismic performance, and the core plate undergoes larger deformation when the neutral axis is close to the top flange. Finally, finite-element models of the test specimens were established and validated using the test hysteretic curves and the failure modes to further investigate the test results.