Development on Rubber Bearings for Sodium-Cooled Fast Reactor: Part 5 — Non-Linear Analytical Models for Thick Rubber Bearing

Volume 8: Seismic Engineering ◽

10.1115/pvp2017-65655 ◽

2017 ◽

Author(s):

Tsutomu Hirotani ◽

Takahiro Mori ◽

Tsuyoshi Fukasawa ◽

Shigeki Okamura ◽

Tomohiko Yamamoto ◽

...

Keyword(s):

Vertical Direction ◽

Analytical Models ◽

Test Results ◽

3D Fem ◽

Restoring Force ◽

Fem Model ◽

Rubber Bearing ◽

Non Linear ◽

Rubber Bearings ◽

Breaking Points

Application of seismic isolation system is essential to reduce the seismic force not only for the horizontal direction but also for vertical direction since the component installed to the Sodium-Cooled-Fast-Reactor (SFR) has thin-walled structures to reduce thermal stress. The authors have performed static loading tests using a half-scale thick rubber bearing to investigate ultimate properties include breaking, and confirmed that the thick rubber bearings have sufficient performance compared to the conventional thin rubber bearings. The present paper describes the evaluation of analytical models for the thick rubber bearing by following two approaches based on the obtained test results. a) Spring model Horizontal and vertical spring models, which are employed to the non-linear seismic response analysis, are compiled to examine applicability of conventional analytical model for thin rubber bearing. In addition, the horizontal and vertical spring models are modified, as a suitable non-linear analytical model for the thick rubber bearing. For the horizontal direction, hysteresis rules composed of multiple lines considering slip effect are modified to correspond to the hysteresis characteristics obtained test results. Hysteresis rules under vertical direction composed of multiple lines in consideration of effect on the shear strain due to horizontal seismic response is constructed. b) 3D FEM model The prediction methods of break strain for thin rubber bearings as the conventional rubber bearing have been examined, which have been proposed by the authors as 3D finite element analysis in consideration of the hyper elasticity. To improve suitable the above mentioned methods for the corresponding the restoring force characteristics for thick rubber bearing, 3D FEM model containing a higher-order elements was constructed to express the skeleton curve as restoring force characteristics up to the breaking points. The validity of the constructed 3D FEM model was investigated comparing breaking test results under horizontal and vertical direction. Consequently, the analytical results demonstrated that the skeleton curves up to the horizontal and vertical breaking points can express with constructed 3D FEM model. In addition, this paper describes the criteria with respect to the breaking strain by utilizing the analytical results.

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THE EFFECTS ON SHAPE-MODELING OF CONCRETE GRAVITY DAMS IN EARTHQUAKE RESPONSE ANALYSES

Proceedings of International Structural Engineering and Construction ◽

10.14455/isec.res.2015.134 ◽

2015 ◽

Vol 2 (1) ◽

Author(s):

Tatsuo Nishiuchi

Keyword(s):

Seismic Response ◽

High Elevation ◽

Earthquake Response ◽

Basement Rock ◽

Gravity Dams ◽

3D Fem ◽

Fem Model ◽

Concrete Gravity Dams ◽

Contraction Joints ◽

Non Linear

To clarify the effects of seismic response of concrete gravity dams under large earthquake, finite element method (FEM) analyses were carried out. In analyses, the height of dam and material properties of concrete and basement rock are same. The 2-dimensional (2D) and the 3-dimensional (3D) FEM model were made and used in earthquake response analyses. The contraction joints between dam block are concerned in 3D non-linear FEM analysis. In the case of same height of dam, the numerical results of damage states and placements in dam are different between 2D FEM model and 3D FEM model, due to the effect of difference in vibration mode of dam. In the 2D FEM model, the damage of top in cross-section becomes remarkable. In the 3D FEM model, the damage of attachment between dam body and basement rock at high-elevation becomes remarkable. The damage of 3D FEM model is smaller than that of 2D FEM model for the same acceleration level of earthquake. The influence of seismic response on contraction joints of 3D non-linear FEM dam model is smaller, which is as same as that of 3D linear FEM dam model. From the above results, the 2D FEM model gives a conservative assessment compared to the 3D FEM model.

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Research and Development of Rubber Bearings for Sodium-Cooled Fast Reactor: Ultimate Properties of Half-Scale Thick Rubber Bearings Based on Breaking Tests

Journal of Pressure Vessel Technology ◽

10.1115/1.4038435 ◽

2017 ◽

Vol 140 (1) ◽

Cited By ~ 1

Author(s):

Tsuyoshi Fukasawa ◽

Shigeki Okamura ◽

Tomohiko Yamamoto ◽

Nobuchika Kawasaki ◽

Tsutomu Hirotani ◽

...

Keyword(s):

Fast Reactor ◽

Static Loading ◽

Restoring Force ◽

Natural Period ◽

Safety Margins ◽

Ultimate Properties ◽

Loading Tests ◽

Rubber Bearings ◽

Breaking Points ◽

Force Characteristics

This paper describes the results of static loading tests using a half-scale thick rubber bearing to investigate ultimate properties application for a sodium-cooled-fast-reactor (SFR). Thick rubber bearings which have a rubber layer that is roughly two times thicker in comparison with existing rubber bearings have been developed by the authors to ensure seismic safety margins for components installed in the reactor building, and to reduce the seismic response in the vertical direction as well as the horizontal direction. The thick rubber bearings, 1600 mm in diameter at the full scale, have been designed to provide a rated load of about 10,000 kN, at the compressive stress of 5.0 MPa, with a horizontal natural period of 3.4 s and a vertical natural period of about 0.133 s. The restoring-force characteristics, including variations, and breaking points, for the thick rubber bearings have not been cleared yet. These validations are essential from the point of view of probabilistic risk assessment (PRA) for a base-isolated nuclear plant as well as a verification of the structural integrity of the thick rubber bearings. The purpose of this paper is to indicate the variation of the stiffness and damping ratios for restoring force characteristics, and the breaking strain or stress, as ultimate properties through static loading tests using half-scale thick rubber bearings. In addition, an analytical model for the thick rubber bearings which is able to express the nonlinear restoring force, including the breaking points, is presented.

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Development on Rubber Bearings for Sodium-Cooled Fast Reactor: Part 3 — Ultimate Properties of a Half Scale Thick Rubber Bearings Based on Breaking Test

Volume 8: Seismic Engineering ◽

10.1115/pvp2016-63397 ◽

2016 ◽

Cited By ~ 1

Author(s):

Tsuyoshi Fukasawa ◽

Shigeki Okamura ◽

Tomohiko Yamamoto ◽

Nobuchika Kawasaki ◽

Tsutomu Hirotani ◽

...

Keyword(s):

Fast Reactor ◽

Static Loading ◽

Restoring Force ◽

Natural Period ◽

Rubber Bearing ◽

Safety Margins ◽

Ultimate Properties ◽

Loading Tests ◽

Rubber Bearings ◽

Force Characteristics

This paper describes the results of static loading tests using a half-scale thick rubber bearing to investigate ultimate properties application for a Sodium-cooled-Fast-Reactor (SFR). The thick rubber bearing, which has a rubber layer roughly three times thicker in comparison with conventional rubber bearings, has been developed by the authors to ensure seismic safety margins for components installed in the reactor building, and to reduce seismic response in the vertical direction as well as horizontal direction. The thick rubber bearings, 1600 mm in diameter at full scale, have been designed to provide a rated load of about 10000 kN with a horizontal natural period of 3.4 s and a vertical natural period of about 0.133 s. The fundamental restoring-force characteristics of the thick rubber bearings has been already cleared through the static loading tests using a half-scale thick rubber bearing, 800 mm in diameter. However, variations of the restoring force characteristics and ultimate properties have not been obtained yet. These validations are essential from the point of view of Probabilistic Risk Assessment (PRA) for a base isolated nuclear plant as well as to verify the structural integrity of the thick rubber bearing. The purpose of this paper is to indicate the variation of the stiffness and damping ratio concerning restoring force characteristics and the breaking strain or stress as ultimate properties through static loading tests using the half-scale thick rubber bearings.

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A non-linear 3D FEM model to simulate timber–concrete joints

Advances in Engineering Software ◽

10.1016/j.advengsoft.2006.08.024 ◽

2007 ◽

Vol 38 (8-9) ◽

pp. 522-530 ◽

Cited By ~ 49

Author(s):

A.M.P.G. Dias ◽

J.W. Van de Kuilen ◽

S. Lopes ◽

H. Cruz

Keyword(s):

3D Fem ◽

Fem Model ◽

Non Linear ◽

Concrete Joints

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Investigation of Dynamic Stray Capacitance and Circuit Network Model for Planar Inductor with Nanocrystal Magnetic Core

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.194-196.2388 ◽

2011 ◽

Vol 194-196 ◽

pp. 2388-2395

Author(s):

Jian Yong Lou ◽

Fei Dang ◽

Lin Gao ◽

Chun Ping Niu ◽

Fang Jun Jiao

Keyword(s):

Equivalent Circuit ◽

Network Model ◽

Circuit Simulation ◽

Magnetic Core ◽

Soft Magnetic Materials ◽

Test Results ◽

Stray Capacitance ◽

3D Fem ◽

Fem Model ◽

Magnetic Components

It is the tendency to adopt novel soft magnetic materials in planar magnetic components to have much more attractive features. In this paper, the nanocrystal magnetic strip is used to consist of magnetic core of planar inductor. A novel network model for dynamic stray capacitances of planar inductor with matrix structure is presented. The magnetic core is taken into account to be one part of the equivalent circuit of planar inductor in high frequency, and its electric potential is considered to be suspended. To analyze the dynamic stray capacitance accurately, the 3D FEM model is adopted, and the parameters for dynamic stray capacitance of inductor windings are obtained. By equivalent circuit simulation of planar inductor, the impedance feature of planar inductor is obtained. The test results by impedance analyzer verify the dynamic capacitance network model.

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Failure Modes of Serially Isolated System under Large Deformation

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.137.30 ◽

2011 ◽

Vol 137 ◽

pp. 30-35

Author(s):

Yong Feng Du ◽

Zhi Dan Lin ◽

Qian Kun Zhu

Keyword(s):

Large Deformation ◽

Failure Modes ◽

Linear Equations ◽

Isolation System ◽

Differential Quadrature Element Method ◽

Quadrature Element Method ◽

Rubber Bearing ◽

Non Linear ◽

Rubber Bearings ◽

Non Linear Equations

This paper investigates the failure modes of serially connected isolation system that the rubber bearing connected with the basement column, under large deformation. Base on Haringx theory and Timoshenko beam modal, the geometrically non-linear equations of serially connected isolation system with one end clamped and the other glided, subjected to a terminal force, are formulated. By using differential quadrature element method (DQEM), the non-linear equations are solved numerically and the configurations of the deformed column are presented. The results show that the large deformation of serially connected isolation system mainly occurred in the rubber bearings. The buckling of rubber bearing is the main failure mode of the serially connected isolated system.

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Numerical Analysis of Hydrodynamic Lubrication on Water-Lubricated Rubber Bearings

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.299-300.12 ◽

2011 ◽

Vol 299-300 ◽

pp. 12-16 ◽

Cited By ~ 4

Author(s):

You Qiang Wang ◽

Chao Li

Keyword(s):

Hydrodynamic Lubrication ◽

Load Capacity ◽

Test Results ◽

Eccentricity Ratio ◽

Special Configuration ◽

Rubber Bearing ◽

Low Load ◽

Rubber Bearings ◽

The Given ◽

Good Agreement

Water lubricated rubber bearings are one of the most appropriate bearings for underwater use. The most popular design used widely today is the straight fluted rubber bearing. The special configuration leads to partial hydrodynamic lubrication and low load capacity. A new bearing bush structure which is favorable for constructing continuous hydrodynamic lubrication was designed and produced for experiment in the paper. The eccentricity ratio of the new structure rubber bearing was measured under different loads in experiment. Used the measured eccentricity ratios, the load capacity was calculated by numerical simulation and compared with the given test values. The calculated values were in good agreement with the given test results. The results show that complete hydrodynamic lubrication can be formed in the new designed rubber bearing. The experimental results also indicate that there is an appropriate bearing clearance which the load capacity is up to the maximum.

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Restoring Force Characteristics of Laminated Rubber Bearings Under Various Restraining Conditions

Journal of Pressure Vessel Technology ◽

10.1115/1.1637643 ◽

2004 ◽

Vol 126 (1) ◽

pp. 141-147

Author(s):

Nobuo Masaki ◽

Shigenobu Suzuki

Keyword(s):

Bending Moment ◽

Combined Loading ◽

Loading Test ◽

Restoring Force ◽

Shape Factors ◽

Rubber Bearing ◽

Laminated Rubber Bearing ◽

Degree Of Restraint ◽

Rubber Bearings ◽

Force Characteristics

We conducted the measurement of restoring force characteristics of laminated rubber bearings under various restraining conditions. In the experiment, we provided three laminated rubber bearings with various second shape factors S2=3,4,4.94. The restoring force is obtained by using a newly designed combined loading test apparatus. By using this apparatus, the laminated rubber bearing could be subjected to shear, compressive and rotational deformations independently. In this experiment, we defined the degree of restraint as the ratio of the bending moment to the restricting bending moment which was measured when the rotation angle of the laminated rubber bearing was zero radian. This means that the flanges on both sides of the laminated rubber bearings were kept parallel during horizontal deformations. From the experiment, it was confirmed that restoring force characteristics were affected by the degree of restraint. Some reduction in restoring forces was observed when the degree of restraint was small. In particular the laminated rubber bearing with a small second shape factor, namely the rubber bearing, had a slender shape, easily buckling under small horizontal displacement. It was also confirmed that bending stiffness of the laminated rubber bearing had shear strain dependency and vertical load i.e., surface pressure dependency. The results of this experiment reveal that we should consider the reduction of the restoring force if the upper or lower structure of the laminated rubber bearing is not sufficiently rigid.

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Theoretical analysis and experimental research on multi-layer elastic damping track structure

Advances in Mechanical Engineering ◽

10.1177/1687814021994975 ◽

2021 ◽

Vol 13 (2) ◽

pp. 168781402199497

Author(s):

Guanghui Xu ◽

Shengkai Su ◽

Anbin Wang ◽

Ruolin Hu

Keyword(s):

Finite Element ◽

Analytical Solution ◽

Finite Element Simulation ◽

Reaction Force ◽

Vibration Reduction ◽

Vertical Direction ◽

Propagation Path ◽

Track Structure ◽

Test Results ◽

Element Simulation

The increase of axle load and train speed would cause intense wheelrail interactions, and lead to potential vibration related problems in train operation. For the low-frequency vibration reduction of a track system, a multi-layer track structure was proposed and analyzed theoretically and experimentally. Firstly, the analytical solution was derived theoretically, and followed by a parametric analysis to verify the vibration reduction performance. Then, a finite element simulation is carried out to highlight the influence of the tuned slab damper. Finally, the vibration and noise tests are performed to verify the results of the analytical solution and finite element simulation. As the finite element simulation indicates, after installation of the tuned slab damper, the peak reaction force of the foundation can be reduced by 60%, and the peak value of the vertical vibration acceleration would decrease by 50%. The vibration test results show that the insertion losses for the total vibration levels are 13.3 dB in the vertical direction and 21.7 dB in the transverse direction. The noise test results show that the data of each measurement point is smoother and smaller, and the noise in the generating position and propagation path can be reduced by 1.9 dB–5.5 dB.

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