• Title, Summary, Keyword: small-scale model

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A Study on Similitude Law for Pseudodynamic Tests and Shaking Table Tests on Small-scale R/C Models (철근콘크리트 축소모형의 유사동적실험과 진동대 실험을 위한 상사법칙 연구)

  • Yang, Hui-Gwan;Seo, Ju-Won;Cho, Nam-So;Chang, Sung-Pil
    • Proceedings of the Earthquake Engineering Society of Korea Conference
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    • pp.545-552
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    • 2006
  • Small-scale models have been frequently used for seismic performance tests because of limited testing facilities and economic reasons. However, there are not also enough studies on similitude law for analogizing prototype structures accurately with small-scale models, although conventional similitude law based on geometry similitude is not well consistent in their inelastic seismic behaviors. When fabricating prototype and small-scale model of reinforced concrete structures by using the same material, added mass is demanded from a volumetric change and scale factor could be limited due to aggregate size. Therefore, it is desirable to use different materials for small-scale model. In our recent study, a modified similitude law was derived depending on geometric scale factor, equivalent modulus ratio and ultimate strain ratio. And quasi-static and pseudo-dynamic tests on the specimens are carried out using constant and variable modulus ratios, and correlation between prototype and small-scale model is investigated based on their test results. In this study, tests on scaled model of different concrete compressive strength aye carried out. In shaking table tests, added mass can not be varied. Thus, constant added mass on expected maximum displacement was applied and the validity was verified in shaking table tests. And shaking table tests on non-artificial mass model is carried out to settle a limitation of acceleration and the validity was verified in shanking table tests.

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Assessment of Dispersion Coefficients and Downward Positions of Water Spray for Small-Scale Release of Chlorine Gas

  • Jang, Seo-Il;Kim, Youngran;Yu, Wooyun;Shin, Dongil;Park, Kyoshik;Kim, Tae-Ok
    • Journal of the Korean Institute of Gas
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    • v.19 no.1
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    • pp.51-56
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    • 2015
  • To assess downward positions of water spray for the small-scale release of chlorine gas, dispersion coefficients for the Gaussian dispersion model were validated at the small-scale release experiment. And the downwind distances of water spray were assessed with the simulated results. As results, the Gaussian plume model using the Briggs' dispersion coefficient well estimated the dispersed characteristics for small-scale release of chlorine gas. The best adequate downwind position of water spray is the position of the maximum concentration of chlorine at the ground level. And the adequate vertical and horizontal dimensions of water spray consider the maximum width and height of cloud.

Flexural Performance of Full-scale RC Beams Strengthened with Different Amount of FRP Composite (FRP복합체로 보강된 실물모형 RC보의 보강재 강성에 따른 휨 보강성능)

  • Choi, Ki-Sun;You, Young-Chan;Kim, Keung-Hwan
    • Proceedings of the Korea Concrete Institute Conference
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    • pp.125-128
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    • 2006
  • Many research have been carried out concerned with the flexural performance of FRP composite in a various ways. Most of them, however, have used a small-scale specimen, so haven't been fully verified by full-scale model test. In this study, a full-scale RC beam model test for flexural strengthening with CFRP composites has been performed in order to verify test results obtained through a series of small-scale model test with respect to FRP stiffness affecting strengthening performance in the previous studies. A total of 4 specimens have been manufactured including control beam. The specimens strengthened with CFRP composites consist of 3 different CFRP stiffness with 2 types of CFRP composite. Consequently, the purpose of this study is to estimate influence of the size effect of specimens and FRP stiffness on the flexural performance. As a result, the effective strain of FRP composite is inversely proportional to FRP stiffness and ensures the same performance with small-scale model test.

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The use of small scale model testing to compare connection methods of steel purlins

  • Urquhart, Stephen M.;Kavanagh, Kenneth T.
    • Structural Engineering and Mechanics
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    • v.6 no.5
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    • pp.571-582
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    • 1998
  • Testing of steel roof purlins is usually performed on full scale models in large vacuum test rigs. To undertake a comparison between web cleat connected purlins and flange bolted purlins a series of tests were performed on a 1:4 small scale model vacuum test rig. Various modelling issues need to be addressed to ensure reasonable comparison with actual constructed roof framing methods but still be suitable for an economical comparison between the connection methods. Model test results were supported by, and found to be in reasonable agreement with, deflection predictions from computer models based on finite element methods. This paper discusses the testing methods adopted and the value of small scale model testing programs as a means of obtaining comparisons between framing options.

Influence of shear preload on wave propagation in small-scale plates with nanofibers

  • Farajpour, M.R.;Shahidi, A.R.;Farajpour, A.
    • Structural Engineering and Mechanics
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    • v.70 no.4
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    • pp.407-420
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    • 2019
  • In the present work, an attempt is made to explore the effects of shear in-plane preload on the wave propagation response of small-scale plates containing nanofibers. The small-scale system is assumed to be embedded in an elastic matrix. The nonlocal elasticity is utilized in order to develop a size-dependent model of plates. The proposed plate model is able to describe both nanofiber effects and the influences of being at small-scales on the wave propagation response. The size-dependent differential equations are derived for motions along all directions. The size-dependent coupled equations are solved analytically to obtain the phase and group velocities of the small-scale plate under a shear in-plane preload. The effects of this shear preload in conjunction with nanofiber and size effects as well as the influences of the elastic matrix on the wave propagation response are analyzed in detail.

High-Temperature Structural Analysis on the Small-Scale PHE Prototype under the Test Condition of Small-Scale Gas Loop (소형가스루프 시험조건에서 소형 공정열교환기 시제품의 고온구조해석)

  • Song, Kee-nam;Hong, S-D;Park, H-Y
    • Transactions of the Korean Society of Pressure Vessels and Piping
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    • v.8 no.1
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    • pp.1-7
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    • 2012
  • A PHE (Process Heat Exchanger) is a key component required to transfer heat energy of $950^{\circ}C$ generated in a VHTR (Very High Temperature Reactor) to the chemical reaction that yields a large quantity of hydrogen. A small-scale PHE prototype made of Hastelloy-X is being tested in a small-scale gas loop at Korea Atomic Energy Research Institute. In order to properly evaluate the high-temperature structural integrity of the small-scale PHE prototype, it is very important to impose a proper constraint condition on its structural analysis model. For this effort, we tried to impose several constraint conditions on the structural analysis model and consequently fixed a proper and effective displacement constraints.

A study on the Dynamic analysis of 1/5 scale derailment simulator model (소형 탈선 시뮬레이터 축소모델 동특성 해석에 관한 연구)

  • Lee, Se-Yong;Eom, Beom-Gyu;Kang, Bu-Byoung;Lee, Hi-Sung
    • Proceedings of the KSR Conference
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    • pp.337-342
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    • 2011
  • A roller rig has been widely used in the study about dynamic stability and railway safety. However, the cost for constructing the roller rig and the difficulty in adjusting the design parameters for vehicle systems lead to the development of a small scale simulator which is cheaper than the large scale test systems and easy to control the parameters affecting dynamic characteristics of the railway vehicle. For the operation of the small scale test system called a small scale simulator, it is required to investigate the performance and characteristics of the system. This could be achieved by a comparative study between an analysis and an experiment. This paper presented the analytical model which could be used for verifying of the test results and understanding of the physical behavior of the dynamic system comprising the small scale bogie and the simulator.

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Generalized Network Generation Method for Small-World Network and Scale-Free Network (Small-World 망과 Scale-Free 망을 위한 일반적인 망 생성 방법)

  • Lee, Kang-won;Lee, Jae-hoon;Choe, Hye-zin
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.41 no.7
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    • pp.754-764
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    • 2016
  • To understand and analyze SNS(Social Network Service) two important classes of networks, small-world and scale-free networks have gained a lot of research interests. In this study, a generalized network generation method is developed, which can produce small-world network, scale-free network, or network with the properties of both small-world and scale-free by controlling two input parameters. By tuning one parameter we can represent the small-world property and by tuning the other one we can represent both scale-free and small-world properties. For the network measures to represent small-world and scale-free properties clustering coefficient, average shortest path distance and power-law property are used. Using the model proposed in this study we can have more clear understanding about relationships between small-world network and scale-free network. Using numerical examples we have verified the effects of two parameters on clustering coefficient, average shortest path distance and power-law property. Through this investigation it can be shown that small-world network, scale-free network or both can be generated by tuning two input parameters properly.

A Software Process Certification Model of Small sized Software Development Using Scrum (스크럼을 활용한 소규모 소프트웨어 개발 기반의 소프트웨어 프로세스 인증 모델)

  • Song, In-Oh;Rhew, Sung-Yul;Lee, Sung-Eun
    • Journal of the Korea Society of Computer and Information
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    • v.16 no.4
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    • pp.215-223
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    • 2011
  • It is difficult to apply a Software Process Certification to small scale project, because of much activities and documents for manage project and guarantee the qualities in small manpower. This paper presents optimized Software Process Certification Model for small scale software development, a combine Scrum with essential elements of NIPA's(National IT industry Promotion Agency) SP-Certification model. The proposed model defined minimum Activities and Documents for SP Certification. The model that I showed consists of 16 Processes and 58 Activities, and 39 Artifacts are created. As a result of having compared proposed model with a Standard Process of Small Business, I confirmed that a small scale project's burden reduced because Activity decreased 38% and Document decreased 20%. In order to verify the validity of the proposed model, applied it in two small scale projects, and compare with the project by Scrum process only, it finished that systematic management was possible without additional manpower, and reached SP-Certification level 2.

A Study on the Similitude of Material for Small-Scale Model Mix Proportion of Concrete Pavement. (콘크리트 포장 축소모델 배합의 재료적 상사성에 관한 연구)

  • 배주성;고영주;김재경;김평수
    • Proceedings of the Korea Concrete Institute Conference
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    • pp.103-110
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    • 1997
  • The objective of this study is to provide the information on the small-scale model mix proportion when the behavior of prototype concrete pavement is studied through small-scale model experiments. However it is difficult to obtain a model material to simulate the prototype concrete by scaling the individual components according to the laws of similitude. In this paper, the stress-strain behavior in uniaxial compression is used as a means to correlate materials similitude between the prototype and the model concrete. Based on th results of experiments, We compared the stress-strain curves of prototype and model concrete mixes using a nondimensional basis. In order to simulate the stress-strain curves of prototype concrete, it is important that various mix as of model concrete selected properly which are varied from aggregate grading, cement-aggregate and sand-aggregate ratio.

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