Dynamic analysis of seismically excited flexible truss tower with scissor-jack dampers

Abstract

SUMMARY In the proposed work, numerical simulations are conducted to investigate scissor‐jack dampers for controlling vibrations in a seismically excited flexible truss tower. For the scissor‐jack damper, new equations are developed to model the amplification factor that account for large deformations of the damper assembly. The equations are validated using computer‐aided design and are used to investigate the influence of vertical deformations on scissor‐jack damper amplification. Then, seismic analysis is carried out for scissor‐jack dampers installed on a 3D flexible truss tower. To reduce the computational effort, a bi‐model method is employed to represent the 3D truss tower as a dynamically equivalent 2D model. To describe the interaction between the structure and scissor‐jack dampers, the displacement‐dependent amplification factors of the scissor‐jack devices and the corresponding damper forces are calculated at each time step. The response of the tower with scissor‐jack damper systems is simulated for a range of damping and four major earthquakes and time histories of the displacement and absolute acceleration at each level of the tower are obtained. Results indicate that the system is effective in reducing both the displacement and absolute acceleration response of the tower without exceeding damper stroke capacity in most cases, but that damping level and earthquake intensity are important factors in the consideration of scissor‐jack dampers for flexible structures subject to seismic loads. Copyright © 2011 John Wiley & Sons, Ltd.

Damping enhancement principle of inerter system

“…Because of this damping enhancement mechanism, the EDE of an inerter system can dissipate more vibration energy than a bare EDE with the same damping coefficient. This benefit is also desirable for other conventional dampers by purposely employing some additional amplification devices . However, it is unavoidable that conventional amplification devices are accompanied by an increase in complexity in terms of construction and installation; they can only provide the amplification function without any contribution to the energy dissipation or storage by itself, which is different from an inerter.…”

“…This benefit is also desirable for other conventional dampers by purposely employing some additional amplification devices. [72][73][74][75] However, it is unavoidable that conventional amplification devices are accompanied by an increase in complexity in terms of construction and installation; they can only provide the amplification function without any contribution to the energy dissipation or storage by itself, which is different from an inerter. The damping enhancement effect can be treated as an alternative aspect for interpreting the inerter system's damping control mechanism and as a significant advantage of an inerter system over a conventional EDE.…”

Seismic performance assessment of steel frames equipped with a novel passive damper using a new damper performance index

“…Several studies have been carried out in the field of response, optimization and design of structures equipped with passive dampers . Xia and Hanson studied two 10‐story frame structures with ADAS devices with different parameters to find out their performance under seismic loading.…”

“…The IPDs dissipate energy through three mechanisms: steel plastification, infilled metal plastification and friction between the infill and the steel pipes and cover plates. The IPDs add strength and stiffness to structures in addition to energy dissipation capability.Several studies have been carried out in the field of response, optimization and design of structures equipped with passive dampers [18][19][20][21][22][23][24][25][26][27][28][29][30][31][32][33][34][35][36]. Xia and Hanson [18] studied two 10-story frame structures with ADAS devices with different parameters to find out their performance under seismic loading.…”

Proposed Configurations for the Use of Smart Dampers with Bracings in Tall Buildings

“…Lee et al [16] investigated the effectiveness of a toggle brace system that uses MR damper in a building structure for seismic response reduction. Walsh et al [17] conducted numerical simulations to investigate scissor-jack dampers for controlling vibrations in a seismically excited flexible truss tower.…”