Study on Laminated Type Base Isolation Device Using Urethane Erastomer for Practical Application

2015 ◽  
Author(s):  
Kenta Ishihana ◽  
Osamu Furuya ◽  
Kengo Goda ◽  
Shohei Omata
Keyword(s):  
Mechanical Characteristics ◽  
Base Isolation ◽  
Approximate Expression ◽  
Response Analysis ◽  
Loading Test ◽  
Cross Sectional ◽  
Isolation System ◽  
Seismic Safety ◽  
Isolation Device ◽  
Urethane Elastomer

Base isolation system will be aggressively applied to not only architectural and civil structures but also various structures, because the effectiveness on seismic safety had been demonstrated again in the Great East Japan Earthquake. In this study, the research and development of laminated type base isolation device using urethane elastomer has been carried out to upgrade a seismic safety for various structures. The fundamental characteristics have been investigated from several loading test by using various experimental devices, and the design formula for the stiffness and equivalent damping coefficient is formulated as an approximate expression of mechanical characteristics until now. Moreover, the experimental examination for aged deterioration in the urethane material has been continuously carried out. This paper summarizes the mechanical characteristics based on the loading test up to 500% shear strain using experimental specimen with 100×100 mm cross-sectional shape, base isolation effect from time response analysis using nonlinear element model of urethane elastomer and the accelerated aging test for verifying the aging of practical use.

Study on Small-Scale Laminated Type Base Isolation Device Using Urethane Elastomer for Practical Application

2016 ◽  
Author(s):  
Kenta Ishihana ◽  
Osamu Furuya ◽  
Kengo Goda ◽  
Shohei Omata
Keyword(s):  
Seismic Isolation ◽  
Mechanical Characteristics ◽  
Base Isolation ◽  
Small Scale ◽  
Loading Test ◽  
Isolation System ◽  
Seismic Safety ◽  
Base Isolation System ◽  
Isolation Device ◽  
Urethane Elastomer

At the present, base isolation system has been recognized by general earthquake resistant technique since the Great Hanshin Earthquake 1995. The seismic isolation will be aggressively applied to not only architectural and civil structures but also various structures, because the effectiveness on seismic safety had been demonstrated again in the Great East Japan Earthquake. In generally, although the base isolation system is divided into laminated rubber bearing type and friction sliding bearing type. In the case of former type, shape factor, maximum or minimum outer shapes and so on are restricted by the material characteristics in visco-elastic material. In previous study, the research and development of laminated type base isolation device using urethane elastomer was carried out to upgrade a seismic safety for various structures. The fundamental characteristics was investigated from several loading test by using various experimental devices, and the design formula for the stiffness and equivalent damping coefficient is formulated as an approximate expression of mechanical characteristics until now. The mechanical characteristics based on the loading test up to 500% shear strain using experimental specimen with 100 × 100 mm cross-sectional shape. It was confirmed that urethane elastomer is not hardening up to 500% shear strain. Moreover, the experimental examination for aged deterioration in the urethane material has been continuously carried out. As the results, it was confirmed that the laminated type seismic isolation device using urethane elastomer is possible to develop as a practicable device from the stable mechanical properties as considering in design step. In this study, the small-scale laminated type base isolation device using urethane elastomer is advanced to the direction of further technical upgrading and of scale down for light-weight structure as a sever rack. The first stage, basic properties of the urethane elastomer has been investigated by loading test. The second stage, the compression creep test with laminated type base isolation device has been investigated to confirm an effect on light-weight mechanical devices.

Laminated Type Isolation Device for Light Weight Structure Using Urethane Elastomer

2017 ◽  
Author(s):  
Kengo Goda ◽  
Osamu Furuya ◽  
Kohei Imamura ◽  
Kenta Ishihana
Keyword(s):  
Seismic Isolation ◽  
Base Isolation ◽  
Light Weight ◽  
Loading Test ◽  
Isolation System ◽  
Seismic Safety ◽  
Base Isolation System ◽  
Weight Structure ◽  
Isolation Device ◽  
Urethane Elastomer

At the present, base isolation system has been recognized by general earthquake resistant technique since the Great Hanshin Earthquake 1995. The seismic isolation will be aggressively applied to not only architectural and civil structures but also various structures, because the effectiveness on seismic safety had been demonstrated again in the Great East Japan Earthquake. In generally, although the base isolation system is divided into laminated rubber bearing type and friction sliding bearing type. In the case of former type, shape factor, maximum or minimum outer shapes and so on are restricted by the material characteristics in visco-elastic material. In general, the isolation structure is used in high damping rubber. However, we pay attention to base isolation using urethane elastomer. Urethane elastomer has excellent elasticity, mechanical strength, abrasion resistance, weather resistance, oil resistance, impact resistance the absorbent, anti-vibration and excellent low-temperature properties. Furthermore, it is possible to impart various characteristics by a combination of isocyanate and polyol and chain extender, requires no large-scale apparatus, it has the advantage molecular design is easy. In previous study, the research and development of laminated type base isolation device using urethane elastomer was carried out to upgrade a seismic safety for various structures. The fundamental characteristics was investigated from several loading test by using various experimental devices, and the design formula for the stiffness and equivalent damping coefficient is formulated as an approximate expression of mechanical characteristics until now. It was confirmed that urethane elastomer is not hardening up to 500% shear strain. Moreover, the experimental examination for aged deterioration in the urethane material has been continuously carried out. As the results, it was confirmed that the laminated type seismic isolation device using urethane elastomer is possible to develop as a practicable device from the stable mechanical properties as considering in design step. In this study, the small-scale laminated type base isolation device using urethane elastomer is advanced to the direction of further technical upgrading and of scale down for light-weight structure as a sever rack. The first stage, basic properties of the urethane elastomer has been investigated by loading test. Furthermore, the design equation is created by loading test using urethane elastomer. The validity of the design equation has been confirmed. The second stage, the compression creep test with laminated type base isolation device has been investigated to confirm an effect on light-weight mechanical devices.

Research and Development of Damping Device for Light Weight Mechanical Structure Using Damping Effect Caused by Eddy Current

2009 ◽  
Author(s):  
Osamu Furuya ◽  
Keiji Ogata ◽  
Toyohiko Tanaka ◽  
Hiroshi Kurabayashi
Keyword(s):  
Eddy Current ◽  
Base Isolation ◽  
Low Cost ◽  
Control Technique ◽  
Small Scale ◽  
Light Weight ◽  
Isolation System ◽  
Seismic Safety ◽  
Damping Effect ◽  
Kobe Earthquake

A base-isolation and vibration control technique has been applied positively to architectural and civil structures after Kobe earthquake, and now the techniques are adopted as general vibration reduction technique for many structures. In such situation, an application of the vibration attenuation device to the small-scale structure has been carried out actively in recent years. Especially, in the important institution of the cities such as a refuge place, a hospital, a school, an information and a communication institution where function maintenance is needed, it is important to maintain its performance of the machinery and equipment in the facility with an upgrade of structural seismic safety. Moreover, in the future, upgrading of seismic safety of the particular equipments is urgent business. This study has been examined a low cost and compact damping device for base-isolation system of light weight mechanical structures like a computer server rack. In this paper, the experimental and analytical results on the basic performances of the damping device using damping effect by Eddy-Current.

Three Dimensional Seismic Isolation System for Next-Generation Nuclear Power Plant With Rolling Seal Type Air Spring and Hydraulic Rocking Suppression System

2005 ◽  
Author(s):  
Takahiro Shimada ◽  
Junji Suhara ◽  
Kazuhiko Inoue
Keyword(s):  
Dynamic Loading ◽  
Nuclear Power ◽  
Seismic Isolation ◽  
Base Isolation ◽  
Three Dimensional ◽  
Loading Test ◽  
Isolation System ◽  
Ability Test ◽  
Base Isolation System ◽  
Suppression System

Three dimensional (3D) seismic isolation devices have been developed to use for the base isolation system of the heavy building like a nuclear reactor building. The developed seismic isolation system is composed of rolling seal type air springs and the hydraulic type springs with rocking suppression system for vertical base isolation device. In horizontal direction, the same laminated rubber bearings are used as horizontal isolation device for these systems. The performances and the applicability have already been evaluated by the technical feasibility tests and performance tests for each system. In this study, it was evaluated that the performance of the 3D base isolation system with rolling seal type air springs combined with hydraulic rocking suppression devices. A 1/7 scaled model of the 3D base isolation devices were manufactured and some performance test were executed for each device. For the rolling seal type air springs, dynamic loading test was executed with a vibration table, and pressure resistant ability test was executed for reinforced air springs. In the dynamic loading test, it is confirmed that the natural period and damping performance were verified. In the pressure resistant ability test, it is confirmed that the air springs had sufficient strength. For the hydraulic rocking suppression system, forced dynamic loading test was carried out in order to measure the frictional and oil flow resistance force on each cylinder. And the vibration table tests were carried out with supported weight of 228 MN in order to evaluate and to confirm the horizontal and vertical isolation performance, rocking suppression performance, and the applicability of the this seismic isolation system as the combined system. 4 rolling seal type air springs and 4 hydraulic load-carrying cylinders with rocking suppression devices supported the weight. As a result, the proposed system was verified that it could be applied to the actual nuclear power plant building to be target.

Study on Three-Dimensional Seismic Isolation System for Next-Generation Nuclear Power Plant: Hydraulic Three-Dimensional Base Isolation System

2004 ◽  
Author(s):  
Takahiro Shimada ◽  
Tatsuya Fujiwaka ◽  
Satoshi Moro
Keyword(s):  
Seismic Isolation ◽  
Base Isolation ◽  
Three Dimensional ◽  
Dynamic Test ◽  
Development Project ◽  
Response Analysis ◽  
Isolation System ◽  
Actual Structure ◽  
Load Carrying ◽  
The Government

In Japan, a number of three-dimensional base isolation systems have been studied for application to new nuclear plant concepts such as the FBR, but these efforts have not so far yielded practically applicable results. The impeding factor has been the difficulty of obtaining an adequate capacity on the vertical isolator for supporting the mass of an actual structure and for suppressing rocking motion. In this paper, we propose a new three-dimensional isolation system that should solve the foregoing problem. The system is constituted of a set of hydraulic load-carrying cylinders connected to accumulator units containing compressed gas, a set of rocking-suppression cylinders connected in series, and a laminated rubber bearing laid under each load-carrying cylinder. The present paper covers a basic examination for applying the proposed system to a FBR plant now under development in Japan. In order to verify expected system performance, the load-carrying cylinders were first tested independently of rocking-suppression cylinders, and this was followed by integrated dynamic test of the system incorporating both load-carrying and rocking suppression cylinders. Response analysis reflecting the test results has indicated the proposed system to be well applicable to the envisaged commercialized FBR. The study was undertaken as part of a research and development project sponsored by the government for realizing a three-dimensional seismic isolation system applicable to future FBR.

Performance Evaluation of Product Type Magnetic Damper Using Eddy-Current Damping Effect

2011 ◽  
Author(s):  
Osamu Furuya ◽  
Keiji Ogata
Keyword(s):  
Eddy Current ◽  
Base Isolation ◽  
Low Cost ◽  
Vibration Reduction ◽  
Product Type ◽  
Small Scale ◽  
Isolation System ◽  
Seismic Safety ◽  
Damping Effect ◽  
Kobe Earthquake

Response control techniques such as a base-isolation and a vibration control have been a general vibration reduction system for upgrading of seismic safety or habitability improvement in civil and architectural structure after Kobe earthquake. In such state in Japan, an application of the vibration reduction device to a small-scale structure has been carried out actively in recent years. Especially, in the important institution of the cities such as refuge place, hospital, school, information and communication institution where function maintenance is needed, it is important to maintain its performance of the machinery and equipment in the facility with an upgrade of structural seismic safety. Moreover, in the future, upgrading of seismic safety of the particular equipments is urgent business. This study has been examined a compact and low cost damping device for a base-isolation system of light weight mechanical structures like a computer server rack. In this paper, experimental and analytical results on the performances of the product type damping device using damping effect caused by Eddy-Current are described.

Study on Simple Vibration Attenuation System for Light Weight Structure

2007 ◽  
Author(s):  
Osamu Furuya ◽  
Hiroshi Kurabayashi
Keyword(s):  
Large Scale ◽  
Base Isolation ◽  
Scale Structure ◽  
Small Scale ◽  
Response Analysis ◽  
Light Weight ◽  
Seismic Safety ◽  
Small Scale Structure ◽  
Vibration Attenuation ◽  
Weight Structure

Various vibration attenuation methods such as a base isolation and vibration control are suggested as seismic safety technique for large scale architectural and civil structure, and these methods have been practical used now. In recent years, these vibration reduction technology begins to be applied to a small scale structure. In case that the technology is applied to a small scale structure, specifications and a cost of the device must be examined well. In this study, a vibration attenuation system for light weight structure with low cost and simple mechanizm. This paper describes the effectiveness of the proposed vibration attenuation system which was evaluated from preliminary seismic response analysis.

Improvement of the polyurethane spring isolation device for HV post insulators and its evaluation by fragility curves

2021 ◽  
pp. 875529302098196
Author(s):  
Tansu Gökçe ◽  
Engin Orakdöğen ◽  
Ercan Yüksel
Keyword(s):  
Seismic Isolation ◽  
Base Isolation ◽  
Numerical Models ◽  
Fragility Curves ◽  
Low Cost ◽  
Steel Plates ◽  
Isolation System ◽  
Base Isolation System ◽  
Isolation Device ◽  
Seismic Base Isolation

A novel seismic base isolation system has been developed for high-voltage (HV) porcelain post insulators. The seismic isolation device consists of two steel plates, four polyurethane springs, and a steel rod, which are low-cost components compared to the post insulators. Two alternative designs of the device are experimentally and numerically assessed in this article. A simple and robust numerical model consisting of linear line elements and nonlinear springs was generated, and subsequently validated using the experimental results. Incremental dynamic analyses (IDAs) were then performed to obtain fragility curves. Ten historical earthquake profiles, scaled to intensities between 0.1 and 2.0 g, were then applied to the numerical models. The fragility curves, generated according to the latest version of IEEE-693, demonstrate that the seismic isolation devices are highly effective in diminishing the base moment of the porcelain insulator. It should be noted that relatively large displacements at the top of the pole must be accounted for by ensuring adequate slackness in the flexible conductors.

The Isolation Effect Analysis of Base and Story Isolation System in Vertical Seismic Action

2010 ◽  
Vol 163-167 ◽  
pp. 3893-3898
Author(s):  
Shao Wei Duan ◽  
Xiao Wei Tao ◽  
Hai Kuan Liu
Keyword(s):  
Base Isolation ◽  
Material Point ◽  
Isolation Effect ◽  
Seismic Action ◽  
Isolation System ◽  
Effect Analysis ◽  
Base Isolation System ◽  
Isolation Systems ◽  
Material Points ◽  
Isolation Device

Through establishing single material point model of base isolation system and two material points model of story isolation system in vertical earthquake, the isolation effect of base and story isolation system in vertical earthquake are studied. Results show that two kinds of isolation systems cannot effectively keep apart the vertical seismic action, and the effect is amplified on the contrary, especially the position of isolation layers in story structures affect the amplification effect. Compared with the base and story isolation structures, while using the same isolation device, the former is better than the latter in isolating vertical seismic action.

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