• Title, Summary, Keyword: Approach slab

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Performance Evaluation of Removable PC Slab Connection for the Reusable Steel Structural System (강구조 재사용 시스템을 위한 탈부착이 가능한 PC 슬래브 접합부의 성능평가)

  • Shim, Hyun Ju;Oh, Eun Ji;Lee, Eun Taik
    • Journal of Korean Society of Steel Construction
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    • v.25 no.6
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    • pp.649-658
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    • 2013
  • Recently, an urgent issue of the global environment in the 21st century is the well-established paradigm of a sustainable and circulatory system. In the field of construction, it is important to approach sustainablity issues from a structural engineering point of view. The reusable steel structural system, which can adapt to changes in socio-economic conditions and varied demands, realized that the consumption of natural resources was minimized, the environmental load was reduced as much as possible. In order to reuse and recombinant the structural members, removable PC slab connection was introduced. This paper investigates the structural performance and serviceability by the dynamic characteristics of the steel beam to concrete slab connection.

An Approach to Estimate Dielectric Constant of Low-Loss Materials Using Dielectric Slab Loaded Cylindrical Cavity Resonators (유전체 슬랩이 삽입된 원통형 공진기를 이용한 저손실 물질의 유전 상수 측정)

  • Lee, Won-Hui
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.19 no.10
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    • pp.1115-1121
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    • 2008
  • In this paper, dielectric slab loaded cylindrical cavity resonator measurement technique is presented to determine the dielectric constant of a dielectric material. The dielectric constant is measured by the resonant frequency deviation of empty and dielectric slab loaded cavity. Characteristic equations are derived by th exact field analysis. The measurement configurations are formed using HP8719A vector network analyzer and an experimental cylindrical metallic cavity with circular cross-section. The validity of the theory is confirmed by experiments and CST MWS 4.0(3D simulator). The results were in the whole satisfactory. The measured dielectric constant of teflon and bakelite are 2.03 and 4.44, respectively.

FE modelling of low velocity impact on RC and prestressed RC slabs

  • Ganesan, Partheepan;Kumar, S. Venkata Sai
    • Structural Engineering and Mechanics
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    • v.71 no.5
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    • pp.515-524
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    • 2019
  • The present study deals with the simulation of low velocity impact on prestressed and reinforced concrete (RC) slabs supported with different end conditions. The prestress is pre-applied on the RC slab in an analytical approach for the prestressed slab. RC slabs with dimensions $500{\times}600{\times}60mm$, $500{\times}600{\times}80mm$ and $500{\times}600{\times}120mm$ were used by changing support condition in two different ways; (i) Opposite sides simply supported, (ii) Adjacent sides simply supported with opposite corner propped. Deflection response of these specimens were found for the impact due to three different velocities. The effect of grade of concrete on deflection due to the impact of these slabs were also studied. Deflection result of $500{\times}500{\times}50mm$ slab was calculated numerically and compared the result with the available experimental result in literature. Finite element analyses were performed using commercially available ANSYS 16.2 software. The effectiveness of prestressing on impact resistant capacity of RC slabs are demonstrated by the way of comparing the deflection of RC slabs under similar impact loadings.

A new developed approach for EDL induced from a single concentrated force

  • Bekiroglu, Serkan;Arslan, Guray;Sevim, Baris
    • Steel and Composite Structures
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    • v.21 no.5
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    • pp.1105-1119
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    • 2016
  • In this study, it is presented that a new developed approach for equivalent area-distributed loading (EADL) induced from a single concentrated force. For the purpose, a full scale 3D steel formwork system was constructed in laboratory conditions. A developed load transmission platform was put on the formwork system and loaded step by step on the mass center. After each load increment, displacement was measured in several crictical points of the system. The developed platform which was put in to slab of formwork to equivalently distribute the load from a point to the whole slab was constituted using I profiles. A 3D finite element model of the formwork system was analyzed to compare numerical displacement results with experimental ones. In experimental tests,difference among the displacements obtained from reference numerical model (model applied EADL) and main numerical model (model applied single load using a load cell via load transmission platform) is about %13 in avarage. Difference among the displacements obtained from experimental results and main numerical model under 30 kN single load is about %11 in avarage. The results revealed that the displacements obtained experimentally and numerically are dramatically closed to each other. It is highlighted from the study that the developed approach is reliable and useful to get EDL.

A New Approach for the Calculation of Neutron Dose Equivalent Conversion Coefficients for PMMA Slab Phantom (PMMA 평판형 팬텀에서의 중성자 선량당량 환산계수의 새로운 계산법)

  • Kim, Jong-Kyung;Kim, Jong-Oh
    • Journal of Radiation Protection and Research
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    • v.21 no.4
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    • pp.297-311
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    • 1996
  • ANSI decided PMMA slab phantom as a calibration phantom and introduced a conversion coefficient calculation method for it. For photon, the conversion coefficient can be obtained by using backscatter factor and conversion coefficient of the ICRU tissue cube and backscatter factor of the PMMA slab. For neutron, however, the ANSI has not introduced any conversion coefficient calculation method for the PMMA slab. In this work, the ANSI method for the photon conversion coefficient calculation was applied to the neutron conversion coefficient calculation of the PMMA slab. Quality weighted tissue kerma of neutron was applied to calculate the backscatter factors on the ICRU cube and the PMMA slab. The dose conversion coefficient of the ICRU cube was also calculated by using MCNP code. Then, the dose conversion coefficient of the PMMA slab was calculated from two backscatter factors and the dose conversion coefficient of the ICRU cube. The discrepancies of the dose conversion coefficients of the PMMA slab and the ICRU cube were less than 10% except 1eV(20%), 1keV(17%), and 4 MeV(16%).

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Transition Zone Behavioral Characteristics with Increase the Speed of High Speed railroad (고속철도 열차 증속에 따른 접속부 거동특성 분석)

  • Park, Hyo-Sung;Kim, Nak-Seok;Kang, Yun-Suk
    • Proceedings of the KSR Conference
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    • pp.1583-1593
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    • 2011
  • As we see the continuation of the increase in the speed of the High Speed railroad worldwide, there is a concern for a possible problem in the connecting transition zone in the railway infrastructure. Honam High Speed railroad's transition zone in the hub for the rotation structures and other supporting structures such as approach slab, sub slab, approach block, etc. Due to its increase in speed of the design speed, and its important role on the driving stability and credibility of the bearing ground performance, we must seek and fine a prevention plan for a cause of differential settlement, as well as the cause of the derailment. In this dissertation, domestic, as well as international design manuals and the applicability of the control standards are studied. Also through the study target, Honam High Speed railroad zone 4-1, we evaluated the connecting componant of the Yeon-Jeong bridge through the eigenvalue and weight transfer of the train when operated at 300km/h, 350km/h, 400km/h, 450km/h, and were able to achieve detailed assessment by checking track behaviors, looking at various components such as the rotation acceleration according to the inversion of the distance length, displace length, displacement and stress distribution. Through these studied, possibility of operating at 400km/h was evaluated based on the condition of the current design basis.

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Behavior of Steel Box Girder Bridge According to the Placing Sequences of Concrete Slab (I) (강합성 상자형 교량의 바닥판 타설에 따른 거동 연구(I) - 해석모델 및 현장실험 -)

  • Kwak, Hyo Gyoung;Seo, Young Jae;Jung, Chan Mook;Park, Young Ha
    • Journal of Korean Society of Steel Construction
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    • v.12 no.2
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    • pp.123-131
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    • 2000
  • In this study, both experimental and analytical study for behavior of the existing composite steel box girder bridges, constructed along with the procedure of continuous placing slab, are conducted to establish the validity of the proposed model. The layer approach is adopted to determine the equilibrium condition in a section to consider the different material properties and concrete cracking across the sectional depth, and the beam element stiffness is constructed on the basis of the assumed displacement field formulation and the 3-points Gaussian Integration. In addition, the effects of creep and shrinkage of concrete for time-dependent behavior of the bridge are taken into consideration. Finally, both analytical and experimental results are compared.

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Short- and long-term analyses of composite beams with partial interaction stiffened by a longitudinal plate

  • Ranzi, Gianluca
    • Steel and Composite Structures
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    • v.6 no.3
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    • pp.237-255
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    • 2006
  • This paper presents a novel analytical formulation for the analysis of composite beams with partial shear interaction stiffened by a bolted longitudinal plate accounting for time effects, such as creep and shrinkage. The model is derived by means of the principle of virtual work using a displacement-based formulation. The particularity of this approach is that the partial interaction behaviour is assumed to exist between the top slab and the joist as well as between the joist and the bolted longitudinal stiffening plate, therefore leading to a three-layered structural representation. For this purpose, a novel finite element is derived and presented. Its accuracy is validated based on short-and long-term analyses for the particular cases of full shear interaction and partial shear interaction of two layers for which solutions in closed form are available in the literature. A parametric study is carried out considering different stiffening arrangements to investigate the influence on the short-and long-term behaviour of the composite beam of the shear connection stiffness between the concrete slab and the steel joist, the stiffness of the plate-to-beam connection, the properties of the longitudinal plate and the concrete properties. The values of the deflection obtained from the finite element simulations are compared against those calculated using the effective flexural rigidity in accordance with EC5 guidelines for the behaviour of elastic multi-layered beams with flexible connection and it is shown how the latter well predicts the structural response. The proposed numerical examples highlight the ease of use of the proposed approach in determining the effectiveness of different retrofitting solutions at service conditions.