• Title/Summary/Keyword: 수직변위

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Model Tests of Pile Groups in Sand (실내모형실험을 통한 군말뚝기초의 거동분석)

  • 정상훈;정상섬
    • Journal of the Korean Geotechnical Society
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    • v.17 no.6
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    • pp.193-205
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    • 2001
  • In this study the behavior of pile groups is investigated experimentally. Special attention is given to the load transfer characteristics of pile groups and to the evaluation of the group effects under vertical and horizontal loadings. In the laboratory experiments, vertical and lateral loadings were imposed on model piles in sand. Model piles made of PVC embedded in Joomoonjin sand were used in this study. Pile arrangements($2\times2,\; 3\times3$) and pile spacings(2.5D, 5.OD, 7.5D) were considered. Load-transfer curves(t-z, q-z and p-y curves), load-deflection curves and group interaction factors were obtained from the experimental results. The group interaction factors under both vertical and horizontal loadings were proposed for the cases of $2\times2\; and\; 3\times3$ pile groups with varying ratios of pile spacings. p-multipliers in this study were found for the individual piles in $2\times2\; and\; 3\times3$ pile groups.

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Displacement Mapping for the Precise Representation of Protrusion (정확한 돌출 형상의 표현을 위한 변위매핑)

  • Yoo, Byoung-Hyun;Han, Soon-Hung
    • Journal of KIISE:Computer Systems and Theory
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    • v.33 no.10
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    • pp.777-788
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    • 2006
  • This paper describes a displacement mapping technique which represents protruded shapes on the surface of an object. Previous approaches for image-based displacement mapping can represent only shapes depressed from the polygon surface. The proposed technique can represent shapes protruded from the underlying surface in real-time. Two auxiliary surfaces which are perpendicular to the underlying surface are added along the boundary of the polygon surface, in order to represent the pixels which overflow over the boundary of the polygon surface. The proposed approach can represent accurate silhouette of protruded shape. It can represent not only smooth displacement of protruded shape, but also abrupt displacement such as perpendicular protrusion by means of adding the supplementary texture information to the steep surface of protruded shape. By per-pixel instructions on the programmable GPU this approach can be executed in real-time. It provides an effective solution for the representation of protruded shape such as high-rise buildings on the ground.

Dynamic Response and Reinforcement of the Railway Plate Girder Bridges (무도상 철도판형교의 동적응답특성 및 보강방안)

  • Hwang, Won Sup;Cho, Eun Sang;Oh, Ji Taek;Kim, Hyun Min
    • Journal of Korean Society of Steel Construction
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    • v.19 no.3
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    • pp.281-290
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    • 2007
  • In this paper, the dynamic behavior of a 12m plate girder railway bridge is analyzed using the commercial FEM program. A time history load is applied to a standard train load via the shape function ofthe beam element. In addition, lateral behavior characteristics were simulated using the Klingel sine movement. A feasibility study of the FEM program and an analysis were performed by comparing the displacement and the acceleration, from the experimental data and the results of the FEM analysis. the time history of the lateral and vertical displacements are reflected in the experimental results. Six kinds of reinforcements were studied from the effects of the displacement and the acceleration. The RF-1 model that was applied to the upper lateral bracing system, and the RF-3 model that reinforced the plate, turned out to be the most effective reinforcement methods with respect to weight limits and construction simplification.

Free Vibrations of Tapered Timoshenko Beam by using 4th Order Ordinary Differential Equation (4계 상미분방정식에 의한 변단면 Timoshenko 보의 자유진동)

  • Lee, Byoung-Koo;Park, Kwang-Kyou;Lee, Tae-Eun
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.25 no.3
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    • pp.185-194
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    • 2012
  • This paper deals with free vibrations of the tapered Timoshenko beam in which both the rotatory inertia and shear deformation are included. The cross section of the tapered beam is chosen as the rectangular cross section whose depth is constant but breadth is varied with the parabolic function. The fourth order ordinary differential equation with respect the vertical deflection governing free vibrations of such beam is derived based on the Timoshenko beam theory. This governing equation is solved for determining the natural frequencies corresponding with their mode shapes. In the numerical examples, three end constraints of the hinged-hinged, hinged-clamped and clamped-clamped ends are considered. The effects of various beam parameters on natural frequencies are extensively discussed. The mode shapes of both the deflections and stress resultants are presented, in which the composing rates due to bending rotation and shear deformation are determined.

Development of ETMD(Electromagnetic Tuned Mass Damper) for Smart Control of Structure (구조물 스마트제어를 위한 ETMD(Electromagnetic Tuned Mass Damper)개발)

  • Jeon, Seung-Gon;Heo, Gwang-Hee;Lee, Chin-Ok;Lee, Jae-Hoon;Kim, Dae-Hyuk
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.26 no.3
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    • pp.21-28
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    • 2022
  • The TMD has a simple structure than other vibration control devices and shows excellent control performance for the simple harmonic vibration generated in the structure. However, the vibration control range is narrower than other control devices, making it vulnerable to vibration cycles caused by unexpected external loads. The ETMD developed in this study consisted of Mass with electromagnets. Therefore when supplying a current, the magnetic field is formed to increase the friction force with the friction plate, thereby instantaneously controlling the behavior of the Mass. The experiment was conducted to compare the control performance of the control device by installing the ETMD developed for control performance evaluation in the center of the model simple beam bridge to forced excitation at 3.02 Hz where the maximum bending displacement occurs. As a result of the experiment, ETMD exhibited excellent control performance with a maximum bending displacement attenuation rate of 57.51%.

Inelastic Time History Analysis of an Unbraced 5-Story Steel Framed Structure for Arrangement of Semi-Rigid Connection (반강접 접합부 배치에 따른 비가새 5층 철골골조구조물의 비탄성 시간이력해석)

  • Kang, Suk-Bong;Kim, Sin-Ae
    • Journal of Korean Society of Steel Construction
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    • v.22 no.4
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    • pp.313-324
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    • 2010
  • In this study, an unbraced five-story steel-framed structure was designed in accordance with KBC2005 to understand the features of structural behavior for the arrangement of semi-rigid connections. An inelastic time history analysis of structural models was performed, wherein all the connections were idealized as fully rigid and semi-rigid. Additionally, horizontal and vertical arrangements of semi-rigid connections were used for the models. A fiber model was utilized for the moment-curvature relationship of a steel beam and a column, a three-parameter power model for the moment-rotation angle of the semi-rigid connection, and a three-parameter model for the hysteretic behavior of a steel beam, column, and connection. The base-shear force, top displacement, story drift, required ductility for the connection, maximum bending moment of the column, beam, and connection, and distribution of the plastic hinge were investigated using four earthquake excitations with peak ground acceleration for a mean return period of 2,400 years and for the maximum base-shear force in the pushover analysis of a 5% story drift. The maximum base-shear force and story drift decreased with the outer vertical distribution of the semi-rigid connection, and the required ductility for the connection decreased with the higher horizontal distribution of the semi-rigid connection. The location of the maximum story drift differed in the pushover analysis and the time history analysis, and the magnitude was overestimated in the pushover analysis. The outer vertical distribution of the semi-rigid connection was recommended for the base-shear force, story drift, and required ductility for the connection.

3-D Analysis of Slope by Tension Wire Sensing (Tension Wire 계측을 통한 비탈면의 3차원 거동 분석)

  • Shin, Taeju;Kim, Taesoo;Hwang, Sanggoo;Han, Heuisoo
    • Journal of the Korean GEO-environmental Society
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    • v.16 no.3
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    • pp.41-48
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    • 2015
  • Several sensor systems are used to estimate and predict the slope behaviors, however though slope sensing systems are much up-to-dated compared to before, they are mainly focused on the hardware developing. It means the analyzing software is deficient to apply the examining slope behavior for slope stability. In real case, slope behavior shows the 3-dimensional movement and failure; however the modeling methods for 3-D behavior are more difficult and need more variables. 1-D analysis shows only the length variation, however the real slope makes the 3-D behaviors. To fix the 3-D space coordinate, three values should be determined such as length, horizontal angle and vertical angle. Therefore if the 3-D coordinate system were composed by the points considered of two directions and length, the 3-D space could be separated into horizontal plane and vertical plane. The data from DY-slope in Chungbuk province was analyzed to the developed 3-D coordinate system. It is concluded from the results of 3-D analysis, the slope is generally moving to transverse direction, also the displacements are happening to road and vertical direction at the same time. Presently, the accumulated displacement between sensing points shows small value within 4.3 cm, and the displacements of all sensing points show the similar directions and magnitudes.

Experimental Study on Deformation Resistance Capacity of SY Permanent Steel Form for RC Beam and Girder under Casting Concrete (SY 비탈형 보 거푸집의 콘크리트 타설시 변형저항성능에 관한 실험적 연구)

  • Bae, Kyu-Woong;Shin, Sang-Min
    • Journal of the Korea Institute of Building Construction
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    • v.21 no.6
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    • pp.605-615
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    • 2021
  • Recently, to shorten construction periods and reduce labor costs, the need for a corrugated beam form in the RC structure is being emphasized. The purpose of this study is to evaluate the deformation performance of SY Beam, a newly developed corrugated beam form work, during concrete casting. The standard cross-sectional shape of SY Beam was determined by modeling the deck structure of various thicknesses using the MIDAS GEN program. As a result, the cross-sectional dimensions of the SY Beam were determined to be 400mm and 450mm in width and height, respectively. A total of three SY Beam specimens were fabricated using steel plate thicknesses of 0.8, 1.0, and 1.2mm. The load conditions applied during casting concrete at the actual site are reflected. The vertical and horizontal displacements of the SY beam were measured during concrete casting. As a result, the vertical displacement showed a tendency to decrease as the thickness increased. Considering both vertical and horizontal displacement, the case with steel plate thickness of 1.2mm is the safest and most immediately applicable to the field. In the future, to secure manufacturability, constructability, and economics, the optimum steel plate thickness should be derived, and additional analysis and experimental studies for 1.05, 1.1, and 1.15mm are required.