Exploring the Low Shape Factor Concept to Achieve Three-Dimensional Seismic Isolation

2012 ◽  
Author(s):  
Gordon P. Warn ◽  
Bach Vu
Keyword(s):  
Shape Factor ◽  
Seismic Isolation ◽  
Three Dimensional

Isolation Performance of Intelligent Seismic Isolation System Using Air Bearing

2009 ◽  
Author(s):  
Satoshi Fujita ◽  
Keisuke Minagawa ◽  
Mitsuru Miyazaki ◽  
Go Tanaka ◽  
Toshio Omi ◽  
...  
Keyword(s):  
Seismic Isolation ◽  
Seismic Waves ◽  
Three Dimensional ◽  
Vertical Motion ◽  
Air Bearings ◽  
Natural Period ◽  
Isolation System ◽  
Vertical Excitation ◽  
Long Period ◽  
Isolation Performance

This paper describes three-dimensional isolation performance of seismic isolation system using air bearings. Long period seismic waves having predominant period of from a few seconds to a few ten seconds have recently been observed in various earthquakes. Also resonances of high-rise buildings and sloshing of petroleum tanks in consequence of long period seismic waves have been reported. Therefore the isolation systems having very long natural period or no natural period are required. In a previous paper [1], we proposed an isolation system having no natural period by using air bearings. Additionally we have already reported an introduction of the system, and have investigated horizontal motion during earthquake in the previous paper. It was confirmed by horizontal vibration experiment and simulation in the previous paper that the proposed system had good performance of isolation. However vertical motion should be investigated, because vertical motion varies horizontal frictional force. Therefore this paper describes investigation regarding vertical motion of the proposed system by experiment. At first, a vertical excitation test of the system is carried out so as to investigate vertical dynamic property. Then a three-dimensional vibration test using seismic waves is carried out so as to investigate performance of isolation against three-dimensional seismic waves.

Development and Application of Innovative Anti-Seismic Systems for the Protection of Cultural Heritage: New Achievements of ENEA

2002 ◽  
Author(s):  
M. Indirli ◽  
M. Forni ◽  
A. Martelli ◽  
B. Spadoni ◽  
A. Dusi ◽  
...  
Keyword(s):  
Cultural Heritage ◽  
Seismic Isolation ◽  
New Technology ◽  
Three Dimensional ◽  
Ambient Vibration ◽  
Civil Structures ◽  
Industrial Plants ◽  
Marche Region ◽  
Passive Devices ◽  
New Development

As described in detail at previous ASME-PVP Conferences and also reminded by separate papers presented this year, large efforts have been devoted by the Italian Agency for New Technology, Energy and the Environment (ENEA), with the cooperation of several further members of the Italian Working Group on Seismic Isolation (GLIS), to the development, validation and application of innovative anti-seismic (IAS) techniques since 1988. To date, considered have been base and floor seismic isolation (SI), energy dissipation through various types of passive devices, hydraulic coupling by means of innovative shock transmitters, systems formed by shape memory alloy devices and more recently, semi-active control of vibrations. New activities at ENEA, which are in progress in the framework of both international and national collaborations, concern the development of new IAS techniques of the aforesaid kinds to be applied to: • civil structures and industrial plants; • cultural heritage structures (CUHESs) to be restored or reconstructed, or masterpieces to be seismically protected. Progress of the work performed for civil and industrial structures has been separately presented at this Conference, while this paper deals with the new development, validation and application activities concerning the IAS techniques applicable to the seismic protection of CUHESs, to which particular attention has been devoted by ENEA for several years. The ongoing activities for CUHESs are being performed in the framework of: • PROSEESM, a national project which foresees pilot applications of the IAS techniques to the restoration of CUHESs damaged by the 1997–98 Marche and Umbria earthquakes; • a feasibilily study for the reconstruction in the original site, with SI and the original masonry materials, of Mevale di Visso, a village in the Marche Region destroyed by the aforesaid event; • a study for the design and application of an innovative three-dimensional SI system for seismic and ambient vibration protection of a roman ship excavated at Ercolano, near Naples.

Development of New Constraction Method for LSBWR

2002 ◽  
Author(s):  
H. Heki ◽  
M. Nakamaru ◽  
T. Maruyama ◽  
H. Hirai ◽  
M. Aritomi
Keyword(s):  
Nuclear Power ◽  
Seismic Isolation ◽  
Three Dimensional ◽  
Operating Cycle ◽  
Construction Period ◽  
Hull Structure ◽  
Plant Equipment ◽  
Tokyo Institute ◽  
Institute Of Technology ◽  
Economic Improvement

LSBWR (Long operating cycle Simplified BWR) is a modular, direct cycle, light water cooled, and small power (100–300MWe) reactor. The design considers requirements from foreign utilities as well as from Japanese. LSBWR is currently being developed by Toshiba Corporation and Tokyo Institute of Technology. Major characteristics of the LSBWR are: 1) Long operating cycle (target: over 15 years), 2) Simplified systems and building, 3) Factory fabrication in module. From the perspective of economic improvement of nuclear power plant, it is needed to shorten the plant construction period and to reduce building volume. In designing LSBWR building, a new building structure, where the hull structure of a ship is applied to floors and walls of LSBWR has been studied. Since the hull structure is manufactured at a shipyard, building module that includes plant equipment becomes possible. The application of the hull structure, which can make large modules at a shipyard, is an effective solution to the lack of laborer and economic improvement. LSBWR is a small size BWR, turbine is smaller size and lighter weight than medium or larger size plant. Then, it has been studied to install a reactor and a turbine in the same building for decreasing building volume. From the view point of standardization, whole building is supported by three dimensional seismic isolation mechanism.

Three Dimensional Seismic Isolation System Using Hydraulic Cylinder

2002 ◽  
Author(s):  
Shinichiro Kajii ◽  
Naoki Sawa ◽  
Nobuhiro Kunitake ◽  
K. Umeki
Keyword(s):  
Seismic Isolation ◽  
Three Dimensional ◽  
Vertical Direction ◽  
Hydraulic Cylinder ◽  
Seismic Load ◽  
3D Seismic ◽  
Isolation System ◽  
Response Characteristics ◽  
Seismic Motion ◽  
Hydraulic Cylinders

A three-dimensional (3D) seismic isolation system for FBR building is under development. The proposed vertical isolation system consists form hydraulic cylinders with water-based liquid and accumulators to support large vertical static load and to realize low natural frequency in the vertical direction. For horizontal isolation, laminated rubber isolator or sliding type isolator will be combined. Because the major part of the feasibility of this isolation system depends on the sealing function and durability of the hydraulic cylinder, a series of feasibility tests of the hydraulic cylinder have been conducted to verify the reliability against seismic load and seismic motion. This paper describes the specification of the seismic isolations system, seismic response characteristics and the results of the feasibility tests of the seal. This study was performed as part of a government sponsored R&D project on 3D seismic isolation.

scholarly journals Conduction Shape Factor Models for Three-Dimensional Enclosures

2005 ◽  
Vol 19 (4) ◽  
pp. 527-532 ◽  
Author(s):  
P. Teertstra ◽  
M. M. Yovanovich ◽  
J. R. Culham
Keyword(s):  
Shape Factor ◽  
Three Dimensional ◽  
Factor Models

Study on Three-Dimensional Seismic Isolation System for Next Generation Nuclear Power Plant: Independent Cable Reinforced Rolling-Seal Air Spring

2004 ◽  
Author(s):  
Mitsuru Kageyama ◽  
Yoshihiko Hino ◽  
Satoshi Moro
Keyword(s):  
Power Plant ◽  
Nuclear Power ◽  
Seismic Isolation ◽  
Base Isolation ◽  
Three Dimensional ◽  
Outer Diameter ◽  
Next Generation ◽  
Air Spring ◽  
Isolation System ◽  
Rubber Sheet

In Japan, the development of the next generation NPP has been conducted in recent years. In the equipment/piping design of the plant, seismic condition has been required much more mitigate than before. So, the three-dimensional (abbreviation to 3D) seismic isolation system development has also been conducted since 2000. The superlative 3D base isolation system for the entire building was proposed. The system is composed of cable reinforced air springs, rocking arresters and viscous dampers. Dimensions of the air spring applied to the actual power plant are 8 meters in the outer-diameter and 3.5 meters in height. The allowable half strokes are 1.0 meters in horizontal and 0.5 meters in vertical respectively. The maximum supporting weight for a single device is 70 MN. The inner design air pressure is about 1.8MPa. This air spring has a distinguishing feature, which realizes 3D base isolation with a single device, whose natural periods are about 4 seconds in horizontal and about 3 seconds in vertical. In order to verify the 3D performance of this system, several feasibility tests were conducted. Firstly, 3D shaking table tests were conducted. The test specimen is scaled 1/4 of the actual device. The outer diameter and inner air pressure of air spring is 2 meters and 0.164 MPa. Next, a pressure resistant test for the sub cable, textile sheet and rubber sheet, which composed air spring, were conducted as a full scale model test. Then, air permeation test for the rubber sheet was also conducted. As a result, the proposed system was verified that it could be applied to the actual nuclear power plants.

scholarly journals A liquid spring–magnetorheological damper system under combined axial and shear loading for three-dimensional seismic isolation of structures

2018 ◽  
Vol 29 (18) ◽  
pp. 3517-3532 ◽  
Author(s):  
Sevki Cesmeci ◽  
Faramarz Gordaninejad ◽  
Keri L Ryan ◽  
Walaa Eltahawy
Keyword(s):  
Seismic Isolation ◽  
Theoretical Calculations ◽  
Three Dimensional ◽  
Real Life ◽  
Vertical Component ◽  
Axial Loading ◽  
Shear Loading ◽  
Magnetorheological Damper ◽  
Isolation System ◽  
Fail Safe

This study focuses on experimental investigation of a fail-safe, bi-linear, liquid spring magnetorheological damper system for a three-dimensional earthquake isolation system. The device combines the controllable magnetorheological damping, fail-safe viscous damping, and liquid spring features in a single unit serving as the vertical component of a building isolation system. The bi-linear liquid spring feature provides two different stiffnesses in compression and rebound modes. The higher stiffness in the rebound mode prevents a possible overturning of the structure during rocking mode. For practical application, the device is to be stacked together along with the traditional elastomeric bearings that are currently used to absorb the horizontal ground excitations. An experimental setup is designed to reflect the real-life loading conditions. The 1/4th-scale device is exposed to combined dynamic axial loading (reflecting vertical seismic excitation) and constant shear force that are up to 245 and 28 kN, respectively. The results demonstrate that the device performs successfully under the combined axial and shear loadings and compare well with the theoretical calculations.

An Approach to Three-Dimensional Turbulent Boundary Layers

1966 ◽  
Author(s):  
A. D. Carmichael
Keyword(s):  
Boundary Layer ◽  
Boundary Layers ◽  
Shape Factor ◽  
Basic Assumption ◽  
Three Dimensional ◽  
Cross Flow ◽  
Turbulent Boundary Layers ◽  
Factor H ◽  
Simple Method ◽  
The Cross

A relatively simple method for predicting some of the characteristics of three-dimensional turbulent boundary layers is presented. The basic assumption of the method is that the cross-flow is small. An empirical correlation of a basic shape factor of the cross-flow boundary layer against the streamwise shape factor H is provided. This correlation, together with data for the streamwise boundary layer, is used to predict the cross flow. The solution is very sensitive to the accuracy of the streamwise boundary-layer data which is predicted by conventional two-dimensional methods.

Influence of Blade Aerodynamic Loading on Efficiency of Radial-Inflow Turbines

1992 ◽  
Author(s):  
T. Takamura ◽  
F. Nishiguchi
Keyword(s):  
Shape Factor ◽  
Rotor Blade ◽  
Flow Analysis ◽  
Three Dimensional ◽  
Blade Loading ◽  
Stream Surface ◽  
Turbine Efficiency ◽  
Blade Shape ◽  
Velocity Triangle ◽  
The Mean

This paper describes the relation between turbine efficiency and rotor blade loading parameters. Tests were carried out on 12 kinds of rotors, which had the same inlet velocity triangle and meridional contour, but different blade numbers (8–11) and blade lengths. The momentum thickness and shape factor of the boundary layers obtained from the results of a quasi-three dimensional flow analysis were used as the rotor blade loading parameters. It was found that blade loading could be evaluated by the shape factor at the mean stream surface and that turbine efficiency was affected by the blade shape of the exducer.

Sign in / Sign up

Export Citation Format

Share Document