Study on the mechanical properties of a viscoelastic self-centering brace with rotational displacement amplification and its application in RC frames

Abstract

This paper introduces a novel viscoelastic self-centering brace with a rotational displacement amplification function (VSB-RA), developed to address the issue of limited energy dissipation in traditional self-centering braces. The basic structure and working mechanism of the VSB-RA are detailed. Low-cycle reciprocating loading tests were performed on two types of VSB-RA specimens with different initial amplification angles, and a comprehensive analysis was conducted on their bearing capacity, energy dissipation performance, self-centering capability, and frequency correlation. A refined finite element model was developed in ABAQUS software to simulate the complete test loading process. Nonlinear dynamic time history analysis is then performed on an 8-story reinforced concrete (RC) frame structure with the VSB-RAs using different initial amplification angles. The results demonstrate that the hysteresis curves of the VSB-RA exhibit distinct flag-shaped characteristics and excellent self-centering performance, and its energy dissipation capacity increases exponentially with the decrease of the initial amplification angle. The numerical simulation results of the hysteresis curves align well with experimental findings. The inter-story drift, residual inter-story drift, floor acceleration, and base shear force are effectively controlled in the VSB-RA frame structures compared to the uncontrolled structure. Under rare earthquake actions, the base shear forces of the structure are reduced by 27.2 %, 27.9 %, and 30.7 % at initial amplification angles of 45°, 37.5°, and 30°, respectively.