Experimental investigation and numerical analysis of rotational deformation amplification friction self-centering brace

This study presents a novel self-centering rotational deformation amplification function brace (RDAF-SCB) that is based on the bridge amplification working mechanism. Compared with conventional brace, RDAF-SCB can solve the problem that the conventional self-centering brace has insufficient energy dissipation ability and the deformation amplification damper lacks self-centering function. This paper introduces the basic structure and working mechanism of RDAF-SCB, and conducts low-cycle reversed loading tests on 6 groups of RDAF-SCB specimens under different working conditions to obtain and compare the key performance data of RDAF-SCB, including bearing capacity and hysteretic curve. A numerical simulation is conducted to analyze the influence of key factors on the mechanical behavior of the RDAF-SCB. The results indicate that the established finite element model agrees nicely with the test results, as the initial amplification angle decreases, the RDAF-SCB exhibits better energy dissipation capacity and fuller hysteresis curve. Compared with the model with an initial amplification angle of 45, the RDAF-SCB with an initial amplification angle of 22.5 increases the force by 34.3%, the equivalent viscous damping ratio by 46.1%, and the maximal residual displacement ratio by 73.95% at the maximal forward displacement; when the initial amplification angle is unchanged, increasing the initial pre-pressure of the disc springs increases bearing capacity and decreases the residual deformation; with the increase of the preload force of the bolts, the energy dissipation capacity of the brace is enhanced and the residual deformation is slightly increased.