scholarly journals Study on Seismic Performance of a Mold Transformer through Shaking Table Tests

2020 ◽  
Vol 10 (1) ◽  
pp. 361 ◽  
Author(s):  
Ngoc Hieu Dinh ◽  
Seung-Jae Lee ◽  
Joo-Young Kim ◽  
Kyoung-Kyu Choi
Keyword(s):  
Shaking Table Test ◽  
Damping Ratio ◽  
Time History ◽  
Relative Displacement ◽  
Shaking Table ◽  
Shaking Table Tests ◽  
Acceleration Time ◽  
Boundary Limit ◽  
Acceleration Time Histories ◽  
Operational Test

This study presents an experimental seismic investigation of a 1000 kVA cast resin-type hybrid mold transformer through tri-axial shaking table tests. The input acceleration time histories were generated in accordance with the specifications recommended by the International Code Council Evaluation Services Acceptance Criteria ICC-ES AC156 code, with scaling factors in the range of 25–300%. The damage and the dynamic characteristics of the mold transformer were evaluated in terms of the fundamental frequency, damping ratio, acceleration time history responses, dynamic amplification factors, and relative displacement. The shaking table test results showed that the damage of the mold transformer was mainly governed by the severe slippage of the spacers and the loosening of the linked bolts between the bottom beam and the bed beam. In addition, the maximum relative displacement at the top beam in Y and Z-directions exceeded the boundary limit recommended by the Korean National Radio Research Agency. Moreover, the operational test of the specimen was performed based on the IEC 60076-11 Standard before and after the shaking table test series to ensure the operational capacity of the transformer.

scholarly journals Experimental and Numerical Studies on Sloshing Dynamics of PCS Water Tank of Nuclear Island Building

2018 ◽  
Vol 2018 ◽  
pp. 1-13 ◽  
Author(s):  
Xiaojun Li ◽  
Chenning Song ◽  
Guoliang Zhou ◽  
Chao Wei ◽  
Ming Lu
Keyword(s):  
Shaking Table Test ◽  
Cooling System ◽  
Damping Ratio ◽  
Time History ◽  
Hydrodynamic Pressure ◽  
Test Method ◽  
Shaking Table ◽  
Water Tank ◽  
Scaled Model ◽  
Sloshing Dynamics

Water tank is one important component of passive containment cooling system (PCS) of nuclear island building. The sloshing frequency of water is much less than structure frequency and large-amplitude sloshing occurs easily when subjected to seismic loadings. Therefore, the sloshing dynamics and fluid-structure interaction (FSI) effect of water tank should be considered when the dynamic response of nuclear island building is analyzed. A 1/16 scaled model was designed and the shaking table test was done, in which the hydrodynamic pressure time histories and attenuation data of wave height were recorded. Then the sloshing frequencies and 1st sloshing damping ratio were recognized. Moreover, modal analysis and time history analysis of numerical model were done by ADINA software. By comparing the sloshing frequencies and hydrodynamic pressures, it is proved that the test method is reasonable and the formulation of potential-based fluid elements (PBFE) can be used to simulate FSI effect of nuclear island building.

scholarly journals Seismic Response of Flat Ground and Slope Models through 1 g Shaking Table Tests and Numerical Analysis

2021 ◽  
Vol 11 (4) ◽  
pp. 1875
Author(s):  
Yong Jin ◽  
Hoyeon Kim ◽  
Daehyeon Kim ◽  
Yonghee Lee ◽  
Haksung Kim
Keyword(s):  
Numerical Analysis ◽  
Seismic Waves ◽  
Shaking Table Test ◽  
Time History ◽  
Shaking Table ◽  
Numerical Analyses ◽  
Shaking Table Tests ◽  
Shear Box ◽  
Laminar Shear ◽  
Flat Ground

In order to verify the reliability of numerical analysis, a series of 1 g shaking table tests for flat ground and slope were conducted using a laminar shear box subjected to different seismic waves. Firstly, numerical analyses, using the DEEPSOIL and ABAQUS software, were done to compare the results of flat ground experiments. After that, finite element analyses with ABAQUS were conducted to compare the results of slope experiments. For numerical analyses, considering the influence of the boundary, the concept of adjusted elastic modulus was proposed to improve the simulation results. Based on the analyses, it is found that in terms of acceleration-time history and spectral acceleration, the numerical analysis results are in good agreement with the experiment results. This implies that numerical analysis can capture the dynamic behavior of soil under 1 g shaking table test conditions.

Computer Simulation of the Shaking Table Tests on Harder Soil-Structure Interaction System

2011 ◽  
Vol 261-263 ◽  
pp. 1619-1624
Author(s):  
Pei Zhen Li ◽  
Jing Meng ◽  
Peng Zhao ◽  
Xi Lin Lu
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Soil Structure ◽  
Shaking Table Test ◽  
Shaking Table ◽  
Soil Structure Interaction ◽  
Shaking Table Tests ◽  
Site Condition ◽  
Element Analysis ◽  
Structure Interaction

Shaking table test on soil-structure interaction system in harder site condition is presented briefly in this paper. Three-dimensional finite element analysis on shaking table test is carried out using ANSYS program. The surface-to-surface contact element is taken into consideration for the nonlinearity of the state of the interface of the soil-pile and an equivalent linear model is used for soil behavior. By comparing the results of the finite element analysis with the data from shaking table tests, the computational model is validated. Based on the calculation results, the paper gives the seismic responses under the consideration of soil-structure interaction in harder site condition, including acceleration response, contact analysis on soil pile interface and so on.

Selection and Scaling Time History Records for Performance-Based Design

2017 ◽  
pp. 1-35
Author(s):  
Yasin M. Fahjan ◽  
F. İlknur Kara ◽  
Aydın Mert
Keyword(s):  
Ground Motion ◽  
Strong Ground Motion ◽  
Time History ◽  
Design Code ◽  
Uniform Hazard Spectra ◽  
Acceleration Time ◽  
Acceleration Time Histories ◽  
Recent Developments ◽  
Time Histories ◽  
Strong Ground

Recent developments in performance-based analyses and the high performance of computational facilities have led to an increased trend for utilizing nonlinear time-history analysis in seismic evaluation of the performance of structures. One of the crucial issues of such analysis is the selection of appropriate acceleration time histories set that satisfy design code requirements at a specific site. In literature, there are three sources of acceleration time histories: 1) recorded accelerograms in real earthquakes scaled to match design code spectrum/uniform hazard spectra/conditional mean spectrum, 2) artificial records generated from white noise spectra to satisfy design code spectrum, and 3) synthetic records obtained from seismological models. Due to the increase of available strong ground motion database, using and scaling real recorded accelerograms is becoming one of the most contemporary research issues in this field. In this study, basic methodologies and criteria for selecting strong ground motion time histories are discussed. Design code requirements for scaling are summarized for ASCE/SEI-7-10, EC8 and Turkish Seismic Codes. Examples for scaling earthquake records to uniform hazard spectra are provided.

Shaking Table Test Study of Reinforced Concrete Shear Wall Structure

2017 ◽  
Vol 865 ◽  
pp. 306-312
Author(s):  
Zheng Li ◽  
Heng Zhou ◽  
Li Qin
Keyword(s):  
Numerical Analysis ◽  
Dynamic Characteristics ◽  
Shaking Table Test ◽  
Time History ◽  
Shear Wall ◽  
Shaking Table ◽  
Wall Structure ◽  
Model Structure ◽  
Fixed Base ◽  
Time History Response

A reduced-scale model of 7-story reinforced concrete shear wall structure is made. Shaking-table test of the model is carried out. Two test conditions are considered. In the first condition, fixed base is used. In another condition, soil structure interaction is considered. According to the experimental results, the dynamic characteristic and seismic performance of shear wall structure is studied. The acceleration time history response of model structure is obtained. Based on the time-history response, the dynamic characteristics of model structure are studied by spectrum analysis. The Finite Element Model of actural structure is established by ANSYS. The dynamic characteristics and seismic performance of actural structure are studied. By comparing the experiment results and numerical analysis results under the fixed-base condition, the rationality of the ANSYS model and numerical analysis method of are verified.

Shaking Table Test for Base-Isolated Nuclear Island Structure Model

2017 ◽  
Author(s):  
Yang Jie ◽  
Li ShaoPing ◽  
Yuan Fang ◽  
Xia ZuFeng ◽  
Huang XiaoLin
Keyword(s):  
Shaking Table Test ◽  
Three Dimensional ◽  
Time History ◽  
Response Spectra ◽  
Shaking Table ◽  
Nonlinear Time History Analysis ◽  
Earthquake Simulation ◽  
Maximum Displacement ◽  
Island Structure ◽  
Reduced Scale

In this paper, the base-isolated design of Nuclear Island structure will be introduced, including the general requirement and the goal of the base-isolated design. Integrated assessment has been performed for the base-isolated design of Nuclear Island structure in the earthquake 0.6g. A series of nonlinear time-history analysis were performed to predict the maximum displacement and acceleration of the isolation layer, the maximum stress of the isolation units, and the floor response spectra of each story of the superstructure in the earthquake 0.6g, considering the realistic mechanical properties and the layout of the isolators. In order to provide realistic data to validate the numerical method, a reduced-scale earthquake simulation of base-isolated nuclear structure on a shaking table was carried out. The study was primarily focused on the response of superstructure and the isolation unit. The dynamic characteristic was examined, together with the vibration acceleration and displacement under different levels of seismic wave. The test results of a reduced-scale nuclear island model previously tested on a shaking table were compared with three-dimensional finite element simulation results. The results of this study provide the technical basis for the base-isolated design of Nuclear Island structure.

Experimental Study on the Seismic Response of Subway Station in Soft Ground

2017 ◽  
Vol 11 (05) ◽  
pp. 1750020 ◽  
Author(s):  
Ma Xianfeng ◽  
Wang Guobo ◽  
Wu Jun ◽  
Ji Qianqian
Keyword(s):  
Seismic Response ◽  
Seismic Design ◽  
Shaking Table Test ◽  
Design Method ◽  
Underground Structure ◽  
Response Characteristic ◽  
Shaking Table ◽  
Subway Station ◽  
Soft Ground ◽  
Shaking Table Tests

Shaking table tests were conducted on typical models of subway structures subjected to several seismic shaking time histories to study seismic response of subway structures in soft ground as well as to provide data for validation of seismic design methods for underground structure. Three types of tests were presented herein, namely green field test, subway station test, and test for joint structure between subway station and tunnel. The similitude and modeling aspects of the 1g shaking table test are discussed. The seismic response of Shanghai clay in different depths was examined under different input waves to understand the acceleration amplification feature in both green field and in the presence of underground structure. Damage situation was checked on internal sections of both subway station and tunnels by halving the model structure. Structure deformation was investigated in terms of element strain under different earthquake loadings. The findings from this study provides useful pointers for future shaking table tests on underground structures/facilities, and the seismic response characteristic of underground structure derived from the shaking table test could be helpful for validating seismic design method for subway station.

Shaking Table Tests With Large Test Specimens of Seismically Isolated FBR Plants: Part 2—Damage Test of Reinforced Concrete Wall Structure

2009 ◽  
Author(s):  
Satoru Inaba ◽  
Takuya Anabuki ◽  
Kazutaka Shirai ◽  
Shuichi Yabana ◽  
Seiji Kitamura
Keyword(s):  
Reinforced Concrete ◽  
Seismic Isolation ◽  
Shaking Table Test ◽  
Shaking Table ◽  
Wall Structure ◽  
Shaking Table Tests ◽  
Concrete Wall ◽  
Restoring Force ◽  
Seismically Isolated ◽  
Rubber Bearings

This paper describes the dynamic damage test of a reinforced concrete (RC) wall structure with seismic isolation sysytem. It has been expected that seismically isolated structures are damaged in sudden when the accelerations of the structures exceed a certain level by hardening of the rubber bearings. However, the response behavior and the damage mode have not been observed by experimental test yet. So, shaking table tests were carried out at “E-Defense”, equipping the world’s largest shaking table, located at Miki City, Hyogo prefecture, Japan. The specimen was composed of an upper structure of 600 ton by weight and six lead-rubber bearings (LRBs) of 505 mm in diameter which provide both stiffness and hysteretic damping. The upper structure consisted of a RC mass and four RC walls with counter weight. The RC wall structure was designed so that the damage of the RC wall occurred between the shear force at the hardening of the rubber bearings and that at their breaking. The dimensions of the RC wall were 1600 × 800 × 100 mm (B × H × t). The reinforcement ratios were 2.46% in vertical by D13 (deformed reinforcing bar, 13 mm in diameter) and 1.0% in horizontal by D10. The shaking table test was conducted consecutively by increasing the levels up to 225% of tentative design earthquake motion. Consequently, because of the increase of the structural response by the hardening of the rubber bearings, the damage of the wall structure with seismic isolation system suddenly happened. In addition, the preliminary finite element analysis simulated the test results fairly well, which were the restoring force characteristics, the crack patterns of the RC wall structure and such.

Dynamic Responses of RC Underground Subway Station and Soil during the Strong Earthquake

2011 ◽  
Vol 194-196 ◽  
pp. 2018-2023
Author(s):  
Jin Bian ◽  
Lian Jin Tao ◽  
Wen Pei Wang ◽  
Bo Zhang
Keyword(s):  
Underground Structure ◽  
Time History ◽  
Side Wall ◽  
Relative Displacement ◽  
Shaking Table ◽  
Dynamic Responses ◽  
Subway Station ◽  
Rc Structures ◽  
Underground Subway Station ◽  
Table Model

Underground subway RC structures suffered significant damage during many earthquakes, so it is important to study the seismic behavior on RC subway structure. The shaking table model test is made of the Beijing typical subway station structure. In this article, the test is introduced briefly; then, the acceleration history curves are analyzed. By the test, it is found that the interaction exits between structure and soil. Under the low intensity earthquake, the underground structure will exert a very small influence on soil and vibrates with soil; under the high intensity earthquake, the soil will exert a large thrust on the underground structure and the relative displacement exists between them. Moreover, At the bottom of the structure side wall, the peak acceleration is larger than it in soil around the place, and at the top and middle of the structure side wall, the peak accelerations are smaller than them in soil around the place; with the depth increase, decrease the peak value, the excellence frequency and its amplitude of the acceleration time history.

scholarly journals Shaking Table Tests for Seismic Response of Orthogonal Overlapped Tunnel under Horizontal Seismic Loading

2021 ◽  
Vol 2021 ◽  
pp. 1-19
Author(s):  
Honggang Wu ◽  
Hao Lei ◽  
Tianwen Lai
Keyword(s):  
Dynamic Response ◽  
Seismic Response ◽  
Seismic Wave ◽  
Shaking Table Test ◽  
Shaking Table ◽  
Shaking Table Tests ◽  
Acceleration Response ◽  
Test Device ◽  
Deformation Stages ◽  
Superposition Effect

This paper presents the seismic dynamic response and spectrum characteristics of an orthogonal overlapped tunnel by shaking table tests. First, a prototype of the engineering and shaking table test device, which was used to design details of the experiment, was developed. Then, the sensors used in the test were selected, and the measurement points were arranged. Subsequently, the Wenchuan seismic wave with horizontal direction in different peak ground accelerations was inputted into the model, followed by a short analysis of the seismic response of the overlapped tunnel in the shaking table test as well as the distribution of the peak acceleration. Throughout the studies, the model exhibited obvious deformation stages during the seismic wave loading process, which can be divided into elastic, plastic, plastic enhancement, and failure stage. In particular, the time- and frequency-domain characteristics of the key parts of the tunnel were discussed in detail by using the continuous wavelet transform (CWT) based on the Morlet wavelet as the basis function. We found that the acceleration response was more intense within 25–60 s after the seismic wave was inputted. Furthermore, owing to “the superposition effect,” the seismic response at the crown of the under-crossing tunnel was stronger than that at the invert of the upper-span tunnel. The low and medium frequencies in the transformation of small scales (5–20) significantly affected the overlapped tunnel. These results elucidate the seismic dynamic response of the overlapped tunnel and provide guidance for the design of stabilizing structures for reinforcing tunnels against earthquakes.

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