Study on the performance of a novel rotation-amplified brace and its vibration control for a frame structure

A novel rotation-amplified brace (RAB) with higher energy dissipation capacity is proposed based on the bridge amplification working mechanism to solve the problem that traditional displacement-dependent braces are unable to fully perform under low-intensity earthquakes due to their small deformation. First, the basic construction and working mechanism are introduced. Then, a theoretical model is derived that can precisely predict the hysteretic characteristics of the brace and verified by numerical simulation. Additionally, the mechanical properties of the brace under different initial amplifying angles are presented. Finally, its control effect on a rotation-amplified braced frame (RABF) is studied. The numerical simulation results show that the yield-bearing capacity, maximum bearing capacity, initial stiffness and energy dissipation capacity of RAB significantly increase with decreasing initial amplification angle. Meanwhile, a smaller initial amplification angle can bring out a greater plastic deformation area of the energy-dissipation steel tube to improve the energy dissipation capacity. However, it is necessary to ensure that the ratio of the maximum tensile-compressive capacity meets the limit stipulated by the American Steel Structure Association at 1.3. It is especially noteworthy that the maximum reduction ratio of maximum interstory drift is as high as 61% for the RABF structure with braces in an inverted Vshape arrangement, which further verifies the effectiveness of RAB in improving seismic performance.