• Title/Summary/Keyword: measured displacement

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Evaluation of Displacement-based Approaches for a Shear Wall Structure (전단벽구조체에 대한 변위기반 내진성능법의 평가)

  • 최상현;현창헌;최강룡;김문수
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 2003.10a
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    • pp.465-472
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    • 2003
  • In this paper, the displacement-based seismic design approaches are evaluated utilizing shaking-table test data of a 1:3 scaled reinforced concrete (RC) bearing wall structure Provided by IAEA. The maximum responses of the structure are estimated using the two prominent displacement-based approaches, i.e., the capacity spectrum method and the displacement coefficient method, and compared with the measured responses. For comparison purpose, linear and nonlinear time history analyses and response spectrum analysis are also performed. The results indicate that the capacity spectrum method underestimates the response of the structure In inelastic range while the displacement coefficient method yields reasonable values in general.

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Stator Displacement Analysis of Switched Reluctance Motor Due to Electromagnetic Force According to Switching (스위칭에 따른 전자기 가진력에 의한 스위치드 릴럭턴스 전동기의 고정자 변위해석)

  • Ha, Gyeong-Ho;Hong, Jeong-Pyo;Kim, Gyu-Tak
    • The Transactions of the Korean Institute of Electrical Engineers B
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    • v.49 no.1
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    • pp.20-26
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    • 2000
  • This paper deals with the modal analysis and the displacement of stator due to electromagnetic forces in Switched Reluctance Motor(SRM). A free-free model of the stator based on structural 3-dimensional Finite Element Method(FEM) is used for investigation the natural frequencies and the mode shapes of the stator. In addition, The displacement caused by magnetic force acting on stator pole is analyzed by the structural FEM coupled with the magnetic force. From these results, the resonance speed is obtained by the relation of the natural frequencies of the harmonic frequencies of magnetic force. And, the eccentricity with respect to rotor is predicted from the analysis result of the mechanical displacement of stator. The natural frequencies of stator are compared with experimental ones measured by modal testing.

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Comparative Analysis of 3D Laser Scanning and MEP Layout for Measurement of Horizontal Displacement of Structures (구조물 수평변위 계측을 위한 3D Laser scanning과 MEP layout의 비교 분석)

  • Shim, Hak-Bo;Seok, Won-Kyun;Park, Soon-Jeon
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2020.11a
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    • pp.183-183
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    • 2020
  • MEP layout and 3D Laser scanning are widely used equipment for displacement measurement in construction site. In this study, MEP layout and 3D Laser scanning were used to measure the lateral displacement of the same structure, and then the advantages and disadvantages of each were compared and analyzed. In general, it has been shown that MEP layout can save a lot of time compared to 3D Laser scanning. And it was found that the lateral displacement measurement results measured at a distance of 15m were similar to each other.

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A STUDY ON STRESS DISTRIBUTION IN IMZ IMPLANT WITH A PLASTIC OR A TITANIUM IME USING FINITE ELEMENT ANALYSIS (유한요소법을 이용한 IMZ임플란트의 플라스틱 및 티타늄 IME의 응력분포에 관한 연구)

  • Ha Chi-Yang;Choi Boo-Byung;Woo Yi-Hyung
    • The Journal of Korean Academy of Prosthodontics
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    • v.31 no.4
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    • pp.625-642
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    • 1993
  • Whether stress-absorbing elements are functional in an implant system has been an issue of interest in oral implantology. The unique feature of the IMZ implant system is the planned imitation of the stress-distributing function of the structural unit of the tooth, periodontium, and alveolar bone through the use of an intramobile element(IME). The purpose of this study was to compare the difference in the displacement and the stress distibutions of IMZ implant with a polyoxymethylene(POM) or a titanium IME under static load. Two dimensional finite element analysis(FEA) was applied for this study and two finite element models were created. PATRAN program(DPA Co.,USA), a software for FEA, and SUN-SPARC2GX(SUN Co., USA), a workstation computer, were used. $1Kg/mm^2$ of static load was loaded individually on each three point of crown of implant prosthesis ; central fossa(load 1), mesial cusp tip(load 2), distal cusp tip(load 3), The displacements of X- and Y-axis and total displacement were measured at mesial and distal cusp tips, mesial and distal points between crown and IME, and implant apex. The von Mises stress was measured at mesial and distal points between crown and IME, mesial and distal points between IME and TIE, mesial and distal alveolar crest, the mesial and distal midpoints of implant, and implant apex. The difference in resultant values were compared and evaluated statistically using paired t-test. The results were as follows : 1. Under the load 1, all the displacement of implant with titanium IME at 5 measuring points was larger than that of with POM IME except total and Y-axis displacement at implant apex. And the differences in stress distributions with POM and titanium were varied. 2. Under the load 2, all the displacement of implant with titanium IME at 5 measuring points was larger than that of with POM IME except X-axis displacement at distal cusp tip. And the differences in stress distributions were varied. 3. Under the load 3, all the displacement of implant with titanium IME at 5 measuring points was larger than that of with POM IME except Y-axis displacement at mesial cusp tip. And the differences in stress distributions were varied. 4. For the displacement, there was significant difference statistically only in total displacement (P<0.1), but was no significant difference in X- and Y-axis displacement(P>0.1). For the stress, there was no significant difference among the compared values.

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Estimation of Dynamic Vertical Displacement using Artificial Neural Network and Axial strain in Girder Bridge (인공신경망과 축방향 변형률을 이용한 거더 교량의 동적 수직 변위 추정)

  • Ok, Su Yeol;Moon, Hyun Su;Chun, Pang-Jo;Lim, Yun Mook
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.34 no.6
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    • pp.1655-1665
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    • 2014
  • Dynamic displacements of structures shows general behavior of structures. Generally, It is used to estimate structure condition and trustworthy physical quantity directly. Especially, measuring vertical displacement which is affected by moving load is very important part to find or identify a problem of bridge in advance. However directly measuring vertical displacement of the bridge is difficult because of test conditions and restriction of measuring equipment. In this study, Artificial Neural Network (ANN) is used to suggest estimation method of bridge displacement to overcome constrain conditions, restriction and so on. Horizontal strain and vertical displacement which are measured by appling random moving load on the bridge are applied for learning and verification of ANN. Measured horizontal strain is used to learn ANN to estimate vertical displacement of the bridge. Numerical analysis is used to acquire learning data for axis strain and vertical displacement for applying ANN. Moving load scenario which is made by vehicle type and vehicle distance time using Pearson Type III distribution is applied to analysis modeling to reflect real traffic situation. Estimated vertical displacement in respect of horizontal strain according to learning result using ANN is compared with vertical displacement of experiment and it presents vertical displacement of experiment well.

Change in Center of Pressure According to Gait Improvement of Post-Stroke Hemiplegic Patients: Pilot Study (뇌졸중 후 편마비 환자의 보행능력 향상에 따른 기립 시 질량중심 변화 : 예비연구)

  • Hong, Hae-jin;Kim, Cheol-hyun;Lee, Il-suk;Lee, Dong-hwan;Park, Young-woong;Song, In-ja;Joo, Ji-yong;Sung, Kang-keyng;Lee, Sang-kwan
    • The Journal of Internal Korean Medicine
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    • v.36 no.4
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    • pp.478-485
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    • 2015
  • Objectives: The purpose of this study was to analyze the change of area and average velocity of the center of pressure (COP) according to gait improvement in post-stroke hemiplegic patients.Methods: We measured the area and the average velocity of COP displacement of ten post-stroke hemiplegic patients while they stood quietly on a force plate at the time of dependent and independent gait . We also measured the area and the average velocity of COP displacement of normal persons to verify differences between them and post-stroke hemiplegic patients.Results: The area of COP displacement decreased significantly, and the average velocity of COP displacement tended to decrease, but not significantly. There were significant differences in the area and the average velocity of COP displacement between post-stroke hemiplegic patients and normal persons.Conclusions: The results of this study show that postural control ability improves as gait improves.

Analysis of DIC Platform and Image Quality with FHD for Displacement Measurement (FHD급 DIC 플랫폼의 변위계측용 영상품질 분석)

  • Park, Jongbae;Kang, Mingoo
    • Journal of Internet Computing and Services
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    • v.19 no.1
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    • pp.105-111
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    • 2018
  • This paper presents the analysis of image quality with FHD(Full HD) resolution camera equipped DIC(Digital Image Correlation) platform for the measurement of the architectural structure's relative displacement. DIC platform was designed based on i.MX6 of Freescale. Displacement measurement based on DIC method, the error is affected by image quality factors as pixel number, brightness, contrast, and SNR[dB](Signal to Noise Ratio). The effect were analyzed. The displacement of ROI(Region Of Interest) area within the image was measured by sub-pixel units based on DIC method. The non-contact telemetry property of DIC method, it can be used to long distance non-contact measurement. The various displacement results was measured and analyzed with the image quality factor adjustment according to the distance(25m, 35m, 50m).

Displacement Evaluation of Cable Supported Bridges Using Inclinometers (경사계를 이용한 케이블교량의 변위 산정)

  • Kong, Min Joon;Yun, Jung Hyun;Kang, Seong In;Gil, Heungbae
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.43 no.3
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    • pp.297-308
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    • 2023
  • Displacement of structures is the most important parameter for safety and performance assessment and is measured to use for diagnosis and maintenance of bridges. Usually LVDT, Laser and GNSS are used for displacement measurement but these measurement instruments have problems in terms of field condition and cost. Therefore, in this study, displacements were evaluated using rotational angle measured by inclinometers and the proposed algorithm was experimentally verified. As the result, vertical displacements of cable supported bridges with traffic and temperature load were properly evaluated through the proposed algorithm. Therefore it is considered that the proposed algorithm can be used for displacement measurement by vehicle load test and long term displacement monitoring.

Measurements of Mechanical Behavior of Rough Rice under Impact Loading (벼의 충격(衝擊) 특성(特性)에 관한 연구(硏究))

  • Cha, J.Y.;Koh, H.K.;Noh, S.H.;Kim, M.S.;Kim, Y.H.
    • Journal of Biosystems Engineering
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    • v.14 no.3
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    • pp.207-214
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    • 1989
  • In this study, impact force and angular displacement of the pendulum were measured by the load cell and potentiometer. Mechanical behavior of rough rice under impact loading was able to analyze precisely and efficiently, because measured data were accumulated and handled by the automatic data acquisition system making use of microcomputer system. Impact force and angular displacement were measured with a resolutiln of 1/1500 seconds in time. Mechanical behavior such as force and energy at rupture point of Japonica type and Indica type rough rice were measured with this system. After impact loading, the damage of rough rice was examined with the microphotograph and an allowable impact force was measured. The results obtained in this study are summarized as follows. 1. Machanical behavior of rough rice under impact loading was analyzed precisely and efficiently because measured data were accumulated and handled by this data acquisition system. 2. Rupture force and rupture energy of rough rice were appeared to be the lowest value in the range of 16 to 18 % moisture content, and rupture force and rupture energy of Japonica type were higher than those of Indica type in each level of moisture content. 3. From the result of the damage examined after the impact loading, allowable impact force was the lowest in the range of 16 to 18 % moisture content, and the value of the allowable impact force of Japonica type was higher than that of Indica type in each level of moisture content.

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Characteristics for Horizontal Displacement of Temporary Earth Retaining Wall on Marine Sediments (해성퇴적층 지반의 가시설토류벽 수평변위 특성에 관한 연구)

  • Kim, Younghun;Kim, Chanki;Choi, Sungyeol;Chun, Byungsik
    • Journal of the Korean GEO-environmental Society
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    • v.11 no.11
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    • pp.37-45
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    • 2010
  • In this study, the value of numerical analysis was compared to the measured value of horizontal displacement during construction. And also, the value was reviewed by comparing with numbers calculated by SUNEX program and EXCAV program. When comparing to suggested values of the maximum horizontal displacement in clayey layer, the displacement caused by the IPS system is larger than one by the Strut girder type system. When comparing the result of SUNEX program to that of EXCAV program, the SUNEX program interprets larger value. It could be concluded the result of SUNEX program is closer to the suggested value, 0.5%H, in clayey layer. The result also shows that the internal friction angle(${\Phi}$) is the key factor of developing horizontal displacement rather than type of supporting systems or materials. That means small horizontal displacement occurs in sandy layer having large value of the internal friction angle, whereas vice versa in clayey layer having small value of the internal friction angle. Therefore, the result of EXCAV program is larger in sandy layer and vice versa in clayey layer. When comparing the measured result during construction to the value of 0.5%H, the measured result is 1.4 times greater than the value of 0.5%H. In contrast, the result of SUNEX program is only 78.1% of the value of 0.5%H and the one of EXCAV program is just 18.1% of that. This result shows the calculated value by SUNEX or EXCAV program is smaller than the observed value by measuring during construction. In result, more careful attention is needed to determine the behavior of the ground. To better analyze the behavior of the ground, more precise finite element method is required.