Regenerative Base Isolation With Multi-Resonant Electromagnetic Shunt Dampers

2017 ◽  
Author(s):  
Yalu Pei ◽  
Yilun Liu ◽  
Lei Zuo
Keyword(s):  
Energy Harvesting ◽  
Vibration Isolation ◽  
Base Isolation ◽  
Single Mode ◽  
Relative Displacement ◽  
Ground Acceleration ◽  
Isolation System ◽  
Dual Functional ◽  
Base Isolation System ◽  
Shunt Circuit

Electromagnetic (EM) shunt damping has been recently proposed for dual-functional vibration isolation and energy harvesting. This paper proposed two multi-resonant electromagnetic shunt damper configurations, namely in parallel and in series, with application to the building base isolation system. The electromagnetic shunt circuit parameters were optimized based on the H2 criteria to minimize the RMS relative displacement for the concern of building safety subjected to broad bandwidth ground acceleration excitations. The performance of the proposed multi-resonant electromagnetic shunt dampers was compared with traditional multiple tuned mass dampers (TMDs). It shows that, for multiple TMDs and multi-resonant electromagnetic shunt dampers with 5% total stiffness ratio, the parallel electromagnetic shunt damper can achieve the best vibration isolation performance. Case study of a base-isolated structure was analyzed in both the time and frequency domain to investigate the effectiveness of the multimode electromagnetic shunt resonances. It shows that both multimode shunt circuits outperform the single mode shunt circuit by suppressing the primary and the second vibration modes simultaneously. Comparatively, the parallel shunt damper is more effective in vibration isolation and energy harvesting, and is also more robust in parameter mistuning than the series shunt damper. This paper further experimentally validated the effectiveness of the multi-resonant electromagnetic shunt damper on a scaled-down base-isolated building.

The Material Behavior and Isolation Benefits of Ball Pendulum System

2006 ◽  
Author(s):  
C. S. Tsai ◽  
Ching-Pei Tsou ◽  
Yung-Chang Lin ◽  
Mei-Ju Chen ◽  
Wen-Shin Chen
Keyword(s):  
Base Isolation ◽  
Ground Motions ◽  
Material Behavior ◽  
Shaking Table ◽  
Ground Acceleration ◽  
Isolation System ◽  
Pendulum System ◽  
Damping Material ◽  
Base Isolation System ◽  
Damping Materials

Earthquake ground motions often result in significant seismic disasters. Strong ground motions will not only cause damage, but may also cause the collapse of structures. People have to face up the suffering from the earthquake damage, and the indirect loss which may be more serious than the damage itself. For example, the antique breaks in museum, and the equipment damages in hi-tech industries are often in huge loss. Therefore, in addition to promoting the earthquake-resistant capacity of a structure, it is also important to ensure the safety of the ancient valuable objects and the instruments in structures. For this reason, this study is aimed at a new damped rolling type base isolation system named the ball pendulum system (BPS) to be installed under the motion sensitive equipment and proceeding all related studies. The isolation device can isolate earthquake from buildings or equipments in any direction by rolling motions and damping materials. This study has conducted a series of component tests and shaking table tests for examining the behaviors of materials and earthquake proof benefits. From the experiment results, it is found that this device can reduce more than 80% of acceleration response under earthquakes with peak ground acceleration of 450 gal. So, the new rolling isolation system with a damping material can be recognized as a feasible and promising way in mitigating the seismic response of equipment.

SUGGESTION OF THE MAGNET SOLIDIFICATION FLUID (MSF), AND APPLICATION TO A BASE-ISOLATION SYSTEM

2005 ◽  
Vol 19 (07n09) ◽  
pp. 1499-1505
Author(s):  
NOBORU SUGIMOTO ◽  
TAKANORI KIYOTA ◽  
TAKUMI SASAKI
Keyword(s):  
Magnetic Fluid ◽  
Base Isolation ◽  
Relative Displacement ◽  
The Other ◽  
Mr Fluid ◽  
Isolation System ◽  
Usual Condition ◽  
Isolation Layer ◽  
Base Isolation System ◽  
Excitation Force

In this paper, we suggest the new intelligent fluid applying MR fluid, and new base-isolation system using that new intelligent fluid. At first, new intelligent fluid suggested in this paper as MSF (Magnet Solidification Fluid) consist of some magnetic fluid and special particles. The most remarkable characteristic of the MSF is that this fluid gives stable and optional yield sharing stress by gathering the properties of containing materials. By the way, in the region where the earthquake often occurs, buildings and industrial equipments must be provided for earthquakes. Then, fuse property is considered as the most anticipative idea for base-isolation system at present. That is, base-isolation system holds an upper structure by stable holding force at usual condition or slight earthquake. On the other hand, when a severe earthquake occurs, it releases holding force and insulates transfer of excitation force of earthquake at the isolation layer of system by yielding relative displacement between ground and an upper structure. According to such idea, we developed new base-isolation system utilizing characteristic of MSF.

Study on Multifunctional Base Isolation System Using Air-Floating Technique

2020 ◽  
Author(s):  
Osamu Furuya ◽  
Kiyotaka Takito ◽  
Hiroshi Kurabayashi ◽  
Kunio Sampei ◽  
Koji Yamazaki
Keyword(s):  
Performance Evaluation ◽  
Seismic Isolation ◽  
Vibration Isolation ◽  
Shaking Table Test ◽  
Base Isolation ◽  
Shaking Table ◽  
Response Analysis ◽  
Vibration Isolator ◽  
Isolation System ◽  
Base Isolation System

Abstract Vibration isolation devices are generally applied to equipment that dislikes vibration installed in buildings. Since the vibration isolator is intended for small vibration input, the damage has been frequently confirmed with excessive vibration input such as an huge earthquake motion. Therefore, the development of a seismic isolation device with a vibration isolation function is desired for important equipment and expensive manufacturing equipment. However, the vibration region targeted by the vibration isolator and the vibration region of the seismic input are at completely different levels. In this study, the authors propose a seismic isolation system using air floating technique to cope with such different vibration levels. In this paper, basic concept, basic performance, preliminary performance evaluation by nonlinear time response analysis, and performance evaluation by shaking table test.

An hourglass-type electromagnetic isolator with negative resistance electromagnetic shunt circuit

2020 ◽  
Vol 64 (1-4) ◽  
pp. 549-556
Author(s):  
Yajun Luo ◽  
Linwei Ji ◽  
Yahong Zhang ◽  
Minglong Xu ◽  
Xinong Zhang
Keyword(s):  
Vibration Isolation ◽  
Electromechanical Coupling ◽  
Coupling Effect ◽  
Negative Resistance ◽  
Isolation System ◽  
Amplitude Vibration ◽  
Vibration Responses ◽  
The Stability ◽  
Isolation Performance ◽  
Shunt Circuit

The present work proposed an hourglass-type electromagnetic isolator with negative resistance (NR) shunt circuit to achieve the effective suppression of the micro-amplitude vibration response in various advanced instruments and equipment. By innovatively design of combining the displacement amplifier and the NR electromagnetic shunt circuit, the current new type of vibration isolator not only can effectively solve the problem of micro-amplitude vibration control, but also has significant electromechanical coupling effect, to obtain excellent vibration isolation performance. The design of the isolator and motion relationship is presented firstly. The electromechanical coupling dynamic model of the isolator is also given. Moreover, the optimal design of the NR electromagnetic shunt circuit and the stability analysis of the vibration isolation system are carried out. Finally, the simulation results about the transfer function and vibration responses demonstrated that the isolator has a significant isolation performance.

scholarly journals Influence of Elastomeric Bearings in Tension on the Seismic Performance of Base-Isolated r.c. Buildings

2020 ◽  
Vol 11 (1) ◽  
pp. 82
Author(s):  
Fabio Mazza ◽  
Mirko Mazza
Keyword(s):  
Base Isolation ◽  
Nonlinear Models ◽  
Vertical Component ◽  
Computer Code ◽  
Nonlinear Phenomena ◽  
Isolation System ◽  
Elastomeric Bearings ◽  
Near Fault ◽  
Base Isolation System ◽  
Near Fault Earthquakes

Elastomeric bearings are commonly used in base-isolation systems to protect the structures from earthquake damages. Their design is usually developed by using nonlinear models where only the effects of shear and compressive loads are considered, but uncertainties still remain about consequences of the tensile loads produced by severe earthquakes like the near-fault ones. The present work aims to highlight the relapses of tension on the response of bearings and superstructure. To this end, three-, seven- and ten-storey r.c. framed buildings are designed in line with the current Italian seismic code, with a base-isolation system constituted of High-Damping-Rubber Bearings (HDRBs) designed for three values of the ratio between the vertical and horizontal stiffnesses. Experimental and analytical results available in literature are used to propose a unified nonlinear model of the HDRBs, including cavitation and post-cavitation of the elastomer. Nonlinear incremental dynamic analyses of the test structures are carried out using a homemade computer code, where other models of HDRBs considering only some nonlinear phenomena are implemented. Near-fault earthquakes with comparable horizontal and vertical components, prevailing horizontal component and prevailing vertical component are considered as seismic input. Numerical results highlight that a precautionary estimation of response parameters of the HDRBs is attained referring to the proposed model, while its effects on the nonlinear response of the superstructure are less conservative.

Hysteresis Loops of Base Isolation System - An Overview

2021 ◽  
Vol 879 ◽  
pp. 189-201
Author(s):  
M.A. Amir ◽  
N.H. Hamid
Keyword(s):  
Earthquake Engineering ◽  
Structural Damage ◽  
Base Isolation ◽  
Numerical Models ◽  
Hysteresis Loops ◽  
Human Beings ◽  
Rc Buildings ◽  
Isolation System ◽  
Base Isolation System ◽  
Isolation Systems

Recently, there are a lot of technological developments in the earthquake engineering field to reduce structural damage and one of them is a base isolation system. The base isolation system is one of the best technologies for the safety of human beings and properties under earthquake excitations. The aim of this paper is to review previous research works on simulation of base isolation systems for RC buildings and their efficiency in the safety of these buildings. Base isolation decouples superstructure from substructure to avoid transmission of seismic energy to the superstructure of RC buildings. The most effective way to assess the base isolation system for RC building under different earthquake excitations is by conducting experiment work that consumes more time and money. Many researchers had studied the behavior of base isolation system for structure through modeling the behavior of the base isolation in which base isolator is modeled through numerical models and validated through experimental works. Previous researches on the modeling of base isolation systems of structures had shown similar outcomes as the experimental work. These studies indicate that base isolation is an effective technology in immunization of structures against earthquakes.

Dynamic Nonlinear Analysis of an Hybrid Base Isolation System with Viscous Dampers and Friction Sliders in Parallel

2012 ◽  
Vol 234 ◽  
pp. 96-101 ◽  
Author(s):  
Donato Cancellara ◽  
Fabio de Angelis
Keyword(s):  
Nonlinear Analysis ◽  
Base Isolation ◽  
Three Dimensional ◽  
Time History ◽  
Seismic Action ◽  
Viscous Dampers ◽  
Isolation System ◽  
Fixed Base ◽  
Base Isolation System ◽  
Dynamic Nonlinear Analysis

In the present work we have analyzed a particular base isolation system for the seismic protection of a multi-storey reinforced concrete (RC) building. The viscous dampers and friction sliders are the devices adopted in parallel for realizing the base isolation system. The base isolation structure has been designed and verified according to European seismic code EC8 and by considering for the friction sliders the influence of the sliding velocity on the value of the friction coefficient. A dynamic nonlinear analysis for a three-dimensional base isolated structure has been performed. Recorded accelerograms for bi-directional ground motions have been used which comply with the requirements imposed by EC8 for the representation of a seismic action in a time history analysis. In this paper a comparative analysis is presented between the base isolated structure with the described hybrid base isolation system and the traditional fixed base structure.

Sign in / Sign up

Export Citation Format

Share Document