Hysteretic Performance Analysis of Self-Centering Buckling Restrained Braces Using a Rheological Model

摘要

In this paper, a cyclic elastoplastic model applicable for studying the hysteretic performance of self-centering buckling restrained braces (SC-BRBs) is established based on the rheological analysis method. The linear-elastic pretensioned rods and superelastic shape memory alloy (SMA) pretensioned rods can be taken into account, and the tube stiffness modification coefficient in consideration of fabrication tolerances is introduced in this model. In the proposed rheological model simulating the SC-BRB specimens, the prediction of the hysteretic performance accurately matched the experiments. The proposed rheological model was applied to study the influence of the key structural parameters on the SC-BRB hysteretic performance: the energy dissipation of SC-BRBs with SMA pretensioned rods is superior to that of linear-elastic pretensioned rods; an increase of pretension and the area of the pretensioned rods will have different impacts on the hysteretic performance of SC-BRBs with linear-elastic pretensioned rods and SC-BRBs with SMA pretensioned rods; increasing the section area of the core plate will result in a higher energy dissipation but a weakened self-centering capacity for the SC-BRB; and reducing the initial stiffness of the brace will have little effect on its energy dissipation. (C) 2016 American Society of Civil Engineers.