• Title/Summary/Keyword: Full scale model test

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Flexural Strengthening with Multi-Layer GFRP Sheets on Full-Scale RC Beams (유리섬유쉬트에 의한 실물모형 RC보의 보강매수별 휨 보강효과)

  • You, Young-Chan;Choi, Ki-Sun;Kim, Keung-Hwan
    • Proceedings of the Korea Concrete Institute Conference
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    • 2005.11a
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    • pp.177-180
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    • 2005
  • The specified tensile strength provided by the manufacturer is determined on the basis of the reliable lower limit ($X-3{\sigma}$ : X=average tensile strength, $\sigma$=standard deviation) obtained from the material test results. Most of these data, however, are based on the test results of 1 layer of FRP sheet. Also, the partial strength reduction factor for strengthening RC members with FRP is based on the small-scale model tests. But, the failure mechanisms of small-scale model tests are reported to be different from those of the full-scale tests. This paper present the test results of full-scale RC beams strengthened with multi-layer GFRP sheets up to 3 layer as well as the material tests. From the material tests, it was observed that the average tensile strengths of GFRP sheets are decreased as the number of layer are increased. Also the premature debonding failure of RC beams strengthened with multi-layer GFRP sheets are observed in inverse proportion to the number of GFRP sheets

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Deformation Measurement of Roadbed in Full-scale Field Test to Determine an Optimum Trackbed of High-Speed Railway (고속철도 노반의 최적단면 결정을 위한 실대형 모형시험에서의 노반 변형 계측)

  • Jung, Young-Hoon;Kim, Hak-Sung;Byeon, Bo-Hyeon;Lee, Jin-Wook
    • Proceedings of the KSR Conference
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    • 2011.10a
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    • pp.2821-2829
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    • 2011
  • Since the KTX was in operation in 2004, a number of researches on increasing the train speed have been conducted. Currently, the Honam High-speed train system is designed for the operation velocity of 350km/h. The societal demand expects higher operation speed, whereas the existing construction method and design specification are questioned in the KTX operation in the velocity over 350 km/h. In this study, a full-scale model test was conducted to obtain the preliminary data that is necessary to understand deformation characteristics of the reinforced road bed and the subgrade layers. In the full-scale model test, direct arrival seismic tests, crosshole seimic test, in-situ bender element test and sensing bar test were employed to measure the stiffness and deformation of the trackbed. The systematic analysis on the different set of measurements enhances the understanding of the behavior of the trackbed.

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Wind tunnel tests on flow fields of full-scale railway wind barriers

  • Su, Yang;Xiang, Huoyue;Fang, Chen;Wang, Lei;Li, Yongle
    • Wind and Structures
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    • v.24 no.2
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    • pp.171-184
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    • 2017
  • The present study provides a deeper understanding of the flow fields of a full-scale railway wind barriers by means of a wind tunnel test. First, the drag forces of the three wind barriers were measured using a force sensor, and the drag force coefficients were compared with a similar scale model. On this basis, the mean wind velocity and turbulence upwind and downwind of the wind barriers were measured. The effects of pore size and opening forms of the wind barrier were discussed. The results show that the test of the scaled wind barrier model may be unsafe, and it is suitable to adopt the full-scale wind barrier model. The pore size and the opening forms of wind barriers have a slight influence on the flow fields upwind of the wind barrier but have some influences on the flow fields and power spectra downwind of the wind barrier. The smaller pore size generates a lower turbulence density and value of the power spectrum near the wind barrier, and the porous wind barriers clearly provide better shelter than the bar-type wind barriers.

Full Scale Model Test on Channel Type PC Bridge (찬넬형 PC교의 실물실험 연구)

  • 구민세;황윤국;조현준;유영찬;김정호
    • Proceedings of the Korea Concrete Institute Conference
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    • 1990.10a
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    • pp.89-94
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    • 1990
  • This study was performed to verify the behavior of channel type PC bridge through the full scale model test. It is well known that the behavior of connection is especially important in case of precast multi-beam bridges. In this study, the lateral load distribution capacity was found satisfactory and influenced little either by the type or strength of connections. Analysis results agreed well with test results. Parameter studies were performed based on the test and analysis results.

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Numerical Simulation of Turbulent Flow around KLNG Hull Form with Different Scale Ratio (다른 축척비를 가진 KLNG 선형주위 유동장 시뮬레이션)

  • Ha, Yoon-Jin;Lee, Young-Gill;Kang, Bong-Han
    • Journal of the Society of Naval Architects of Korea
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    • v.51 no.1
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    • pp.8-15
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    • 2014
  • In this study, flow characteristics around the hull form of KLNG are investigated by numerical simulations. The numerical simulations of the turbulent flows with the free surface around KLNG have been carried out at Froude number 0.1964 using the FLUENT 6.3 solver with Reynolds stress turbulence model. Several GEOSIM models are adopted to consider the scale effect attendant on Reynolds number. Furthermore, a full scale ship is calculated and the result is compared with the numerical results of GEOSIM models. The calculated results of GEOSIM models and the full scale ship are compared with the experiment data of MOERI towing tank test and Inha university towing tank test. Moreover, wake distribution on the propeller plane of the full scale ship is estimated using the numerical results of GEOSIM models. The prediction result is directly compared with the simulation result in full scale.

Structural Analysis for 4-Seater Canard Airplane (4인승 선미익기 구조해석)

  • Kim, Sung-Joon;Shim, Jae-Yeul
    • Aerospace Engineering and Technology
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    • v.6 no.2
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    • pp.35-39
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    • 2007
  • In this paper, we have presented structural analysis procedure and full scale test results for 4-seater canard airplane. Construction of the finite element model is critical path for the aircraft structural analysis and directly affects the structural integrity. The refinement of the finite element model should be determined depending on full scale test results. From the results of the structural analysis, 5 design limit loads test conditions and 11 design ultimate loads test conditions were selected. By the presented procedure, the structural integrity of 4-Seater Canard Airplane is successfully obtained.

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Verification of Propeller-Induced Fluctuating Pressure in Sea Trials (실선에서의 프로펠러 변동압력 성능 검증)

  • Song In-Haeng;Seo Jongsoo;Paik Kwangjun;Jung Jaekwon
    • Special Issue of the Society of Naval Architects of Korea
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    • 2005.06a
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    • pp.44-50
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    • 2005
  • Since a cavitation pattern in model scale can be different from that in full scale, it has been highly demanded to measure a fluctuating pressure induced by propeller in full scale. For the verification of the cavitation test for 105K lanker in the large cavitation tunnel in Samsung Ship Model Basin(SSMB), an effective pressure fluctuation measurement system was developed and a series of full scale measurements was carried out. These results were compared with those of cavitation tests in SSMB. The measured results in full scale gave good agreements to those in model tests. The fluctuating pressure at $2^{nd}$ blade frequency in full scale seems to be highly dependent upon tip loading.

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Single piles under cyclic lateral loads - Full scale tests and numerical modelling

  • Hocine Haouari;Ali Bouafia
    • Geomechanics and Engineering
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    • v.32 no.1
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    • pp.21-34
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    • 2023
  • In order to analyze the effect of the cyclic lateral loading on the response of a pile-soil system, a full-scale single steel pile was subjected to one-way cyclic loading. The test pile was driven into a bi-layered soil consisting of a normally consolidated saturated clay overlying a silty sandy layer, the site being submerged by water up to one meter above the mudline in order to reproduce the conditions of an offshore pile foundation. The aim of this paper is to present the main results of interpretation of the cyclic lateral tests in terms of pile deflections, bending moment, and cyclic P-Y curves. From these latter an absolute secant reaction modulus EAS,N was derived and a simple calculation model of the test single pile is proposed based on this modulus. Two applications of the proposed model are carried out, one with a 2D finite element modelling, and the second with a load transfer curves-based method.

Practical scaling method for underwater hydrodynamic model test of submarine

  • Moonesun, Mohammad;Mikhailovich, Korol Yuri;Tahvildarzade, Davood;Javadi, Mehran
    • Journal of Advanced Marine Engineering and Technology
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    • v.38 no.10
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    • pp.1217-1224
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    • 2014
  • This paper provides a practical scaling method to solve an old problem for scaling and developing the speed and resistance of a model to full-scale submarine in fully submerged underwater test. In every experimental test in towing tank, water tunnel and wind tunnel, in the first step, the speed of a model should be scaled to the full-scale vessel (ship or submarine). In the second step, the obtained resistance of the model should be developed. For submarine, there are two modes of movement: surface and submerged mode. There is no matter in surface mode because, according to Froude's law, the ratio of speed of the model to the full-scale vessel is proportional to the square root of lengths (length of the model on the length of the vessel). This leads to a reasonable speed and is not so much for the model that is applicable in the laboratory. The main problem is in submerged mode (fully submerged) that there isn't surface wave effect and therefore, Froude's law couldn't be used. Reynold's similarity is actually impossible to implement because it leads to very high speeds of the model that is impossible in a laboratory and inside the water. According to Reynold's similarity, the ratio of speed of the model to the full-scale vessel is proportional to the ratio of the full-scale length to the model length that leads to a too high speed. This paper proves that there is no need for exact Reynold's similarity because after a special Reynolds, resistance coefficient remains constant. Therefore, there is not compulsion for high speeds of the model. For proving this finding, three groups of results are presented: two cases are based on CFD method, and one case is based on the model test in towing tank. All these three results are presented for three different shapes that can show; this finding is independent of the shapes and geometries. For CFD method, Flow Vision software has been used.

An estimation method of full scale performance for pulling type podded propellers

  • Park, Hyoung-Gil;Choi, Jung-Kyu;Kim, Hyoung-Tae
    • International Journal of Naval Architecture and Ocean Engineering
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    • v.6 no.4
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    • pp.965-980
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    • 2014
  • This paper presents a new estimation method of full scale propulsive performance for the pulling type podded propeller. In order to estimate the drag of pod housing, a drag velocity ratio, which includes the effects of podded propeller loading and Reynolds number, is presented and evaluated through the comparison of model test and numerical analysis. By separating the thrust of propeller blade and the drag of pod housing, extrapolation method of pod housing drag to full scale is deduced, and correction method of propeller blade thrust and torque to full scale is presented. This study utilized the drag coefficient ratio of the pod housing as a measure for expanding it to full scale, but in order to increase the accuracy of performance evaluation, additional study is necessary on the method for the full scale expansion via separating the drag of pod body, strut and fin which consist the pod housing.