Active-passive base isolation system for seismic response controlled structures

1995 ◽  
Author(s):  
Murat Sener ◽  
Senol Utku
Keyword(s):  
Seismic Response ◽  
Base Isolation ◽  
Isolation System ◽  
Base Isolation System ◽  
Controlled Structures

Reduction of Seismic Response of Mechanical System by Base Isolation System With Friction Bearing

2007 ◽  
Author(s):  
Shigeru Aoki ◽  
Yuji Nakanishi ◽  
Kazutoshi Tominaga ◽  
Takeshi Otaka ◽  
Tadashi Nishimura ◽  
...  
Keyword(s):  
Mechanical System ◽  
Seismic Response ◽  
Base Isolation ◽  
Low Frequency ◽  
Simulation Method ◽  
Shaking Table ◽  
Restoring Force ◽  
Isolation System ◽  
Friction Bearing ◽  
Base Isolation System

Reduction of seismic response of mechanical system is important problem for aseismic design. Some types of base isolation systems are developed and used in actual base of buildings and floors in buildings for reduction of seismic response of mechanincal system. In this paper, a base isolation system utilizing bearing with friction and restoring force of bearing is proposed. Friction bearing consists of two plates having spherical concaves and oval type metal or spherical metal with rubber. First, effectiveness of the base isolation system is examined experimentally. Using artificial time histories, the isolated table is shaken on the shaking table. The maximum value of response is reduced and sum of squares of response is significantly reduced. Power spectrum is significantly reduced in almost of all frequency regions, except for very low frequency region. Next, in order to examine reduction of seismic response of actual mechanical system, a console rack is set on the isolated plate. Seismic response is also significantly reduced. Finally, obtained results of experiment are examined by simulation method. An analytical model considering friction and restoring force is used. From simulation method, effectiveness of the proposed base isolation system is demonstrated.

scholarly journals Research on Seismic Response of Base-Isolated Nuclear Island Building considering FSI Effect of PCS Water Tank

2020 ◽  
Vol 2020 ◽  
pp. 1-15
Author(s):  
Chenning Song ◽  
Chao Wei ◽  
Zhi Zhang
Keyword(s):  
Seismic Response ◽  
Base Isolation ◽  
Numerical Models ◽  
Horizontal Displacement ◽  
Reduction Ratio ◽  
Isolation Effect ◽  
Water Tank ◽  
Isolation System ◽  
Base Isolation System ◽  
Natural Frequency Analysis

Base isolation can be used to reduce seismic response of structure and protect the structure from damage subjected to earthquake. To study the isolation effect of new PWR nuclear power plant with a base isolation system, considering FSI (fluid-structure interaction) effect by the simplified model, two 3D numerical models (one nonisolated model and one isolated model) were established. After natural frequency analysis, one artificial ground motion was chosen to analyze isolation effect qualitatively. Based on the results, the accelerations and relative displacements of nuclear island building under ten natural ground motions were statistically analyzed to evaluate the isolation effect quantitatively. The results show that the base isolation system can reduce the natural frequencies of nuclear island building. Horizontal accelerations can be reduced effectively, but the isolation effect is not obvious in vertical direction. The acceleration reduction ratio of the top is about 70%–90%, and the acceleration reduction ratio of the lower part is about 20%–60%. Horizontal displacement of the isolated model is far larger than that of the nonisolated model, and horizontal displacement will become larger considering FSI effect. These conclusions could provide some references for studies on the isolation system of nuclear island building.

21112 Vibration analysis of small base isolation system using friction bearings : Effects of eccentricity on seismic response

2013 ◽  
Vol 2013.19 (0) ◽  
pp. 519-520
Author(s):  
Katsumi Kurita ◽  
Shigeru Aoki ◽  
Yuji Nakanishi ◽  
Kazutoshi Tominaga ◽  
Mitsuo Kanazawa ◽  
...  
Keyword(s):  
Seismic Response ◽  
Vibration Analysis ◽  
Base Isolation ◽  
Isolation System ◽  
Base Isolation System ◽  
Small Base ◽  
Friction Bearings

Influence of the Strain Hardening of HDRBs in the Evaluation of the Seismic Response of a RC Base Isolated Structure

2012 ◽  
Vol 602-604 ◽  
pp. 1546-1554
Author(s):  
Donato Cancellara ◽  
Fabio de Angelis ◽  
Mario Pasquino
Keyword(s):  
Strain Hardening ◽  
Seismic Response ◽  
Base Isolation ◽  
Cyclic Behavior ◽  
Hysteretic Model ◽  
Isolation System ◽  
Limit Value ◽  
Hardening Effect ◽  
Base Isolation System ◽  
Rubber Bearings

In this paper we have analyzed the influence of the strain hardening behavior of High Damping Rubber Bearings (HDRBs) adopted for a base isolation system of a Reinforced Concrete (RC) isolated structure. For the modeling of the rubber isolators we have adopted an evolution of the Bouc-Wen’s hysteretic model taking into account the incremental hardening effect which appears when the shear strain of the HDRB exceeds the limit value around 100% usually adopted in design practice. The incremental hardening effect is sometimes neglected in the design but it is an important aspect because it ensures a seismic protection of the base isolated structure also in presence of exceptional seismic events for intensity or frequency content. In this paper we have highlighted the significant influence of this phenomenon in the seismic response of the isolated structure by reporting the cyclic behavior of a HDRB respectively neglecting and considering this aspect.

Optimization of Second Isolation Period for Parallel Base-Isolated System

2012 ◽  
Vol 256-259 ◽  
pp. 1117-1120
Author(s):  
Q. Rong
Keyword(s):  
Objective Function ◽  
Seismic Response ◽  
Base Isolation ◽  
Energy Scale ◽  
Base Shear ◽  
Isolation System ◽  
Base Isolation System ◽  
Low Amplitude ◽  
Variation Rule ◽  
Isolation Period

The optimization of second isolation period for parallel base isolation system is investigated systematically. The maximum dissipative energy scale factor is used as the objective function, the maximum sliding displacement of base-isolated layer, the residual displacement and the maximum base shear coefficient are considered as the constraining factors. For first to fourth category site, under the low amplitude severe earthquake, the variation rule of the four seismic response indicators for the second isolation period is approximately same, the second isolation period is proposed to be in the range of 4s to 6s.

scholarly journals Seismic Vibration Control of Building with Lead Rubber Bearing Isolator

10.29007/pvzx ◽  
2018 ◽  
Author(s):  
Kishan Bhojani ◽  
Vishal Patel ◽  
Snehal Mevada
Keyword(s):  
Seismic Response ◽  
Base Isolation ◽  
Time History ◽  
Dynamic Parameter ◽  
Base Shear ◽  
Maximum Displacement ◽  
Maximum Acceleration ◽  
Isolation System ◽  
Loma Prieta Earthquake ◽  
Base Isolation System

During the life span of structure there may be an effect of vibration. Due to vibration there may be major or minor damage in building. Base isolation is best method to reduce the seismic response of the structure. This paper gives idea about base isolation system which can be used in multi-story building to reduce seismic response of the structure. This paper represents the initialize study of dynamic parameter like effective damping for four earthquake time history. In this paper the optimum effective damping has been found out under the effect of Loma Prieta earthquake time history. The parametric study has been conducted to evaluate the effect on maximum displacement, maximum acceleration, maximum base shear in bare frame and frame with isolator.

The Computational Analysis and Evaluation on the Seismic Response of Base Isolated Benchmark Building

2012 ◽  
Vol 204-208 ◽  
pp. 2387-2393
Author(s):  
Xiang Zhen Li ◽  
Bing Li ◽  
Huan Chang Fu ◽  
Wei Ming Xiang
Keyword(s):  
Seismic Response ◽  
Computational Analysis ◽  
Base Isolation ◽  
Isolation Effect ◽  
Theoretical Research ◽  
Calculation Methods ◽  
Dynamic Calculation ◽  
Isolation System ◽  
Analysis And Evaluation ◽  
Base Isolation System

Based on the base isolated benchmark building, the dynamic calculation methods of the seismic response were established. Through the computational analysis and comparison of the non-isolation situation and two isolation situations, the influence of the isolation effect about base isolation system stiffness, damping and the method of stiffness arrangement were demonstrated on the platform of benchmark building. The isolated benchmark building was evaluated to offer some new basis about the model used in theoretical research and isolation designed as well as alternative ways to further broaden the base isolated benchmark building.

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