• 제목/요약/키워드: Analytical results

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Analytical Model of Hysteretic Behavior of Reinforced Concrete Members with Relocated and Enlarged Plastic Hinging Zones (소성한지부가 이동 및 확장된 콘크리트부재의 이력거동에 대한 해석모델)

  • 서수연;김윤일;이리형
    • Proceedings of the Korea Concrete Institute Conference
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    • 1990.10a
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    • pp.19-22
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    • 1990
  • Based on the design concept of a "Strong Column - Weak Beam" in the design of reinforced concrete, recently, a design method which moves the plastic hinging zone of a specific length away from the column face, has been proposed for reducing the degradation of stiffness and strength in the beam-column joint. To analyze reinforced concrete structures designed by this method. It is necessary to establish the analytical model which can simulate the hysteretic behavior depended on the initial positions and enlargements of plastic hinges. In this paper, by the numerical assumptions and the regression of experimental results, an analytical model is proposed. To estimate the accuracy of this model, some example analyses are conducted and compared with experimental results. From these comparision. It is shown that the proposed model is a good to predict the behavior of members subjected go cyclic loads.lic loads.

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Time-dependent Material Properties in FCM Segment of Prestressed Concrete Box-Girder Bridge

  • Yoon, Young-Soo;Choi, Han-Tae;Kwon, Soon-Beom
    • KCI Concrete Journal
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    • v.11 no.3
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    • pp.99-107
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    • 1999
  • In designing the Prestressed concrete box-girder bridge. dead load, prestressing force, creep and shrinkage of concrete are the main factors which influence the camber and deflection of segmental concrete structure under construction. Among these factors the creep and shrinkage are the functions of the time-dependent property which. therefore, must be considered with time. The prediction model for estimating creep and shrinkage of concrete has been suggested by ACI, CEB/FIP, JSCE and KSCE design code and EMM, AEMM, RCM, IDM and SSM has been suggested for analytical method in consideration of time-dependent characteristics. In this study the creep test was carried out for four different curing ages of concrete which were applied to the Prestressed concrete structure at the construction site, and the results of test were compared with the values of creep prediction proposed by the design code. Also the creep test was performed with step-wise incremental stresses and the results were compared to the analytical values.

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Analysis of Call Admission Control for Joint Transmission-Based LTE-Advanced Systems (Joint Transmission 기반의 LTE-Advanced 시스템에 대한 호 수락 제어의 성능 분석)

  • Kim, Seung-Yeon;Lee, Hyong-Yoo;Ryu, Seung-Wan
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.38B no.7
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    • pp.535-542
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    • 2013
  • Coordinated multi-point transmission (CoMP) is considered to be a promising technique to improve the throughput for LTE-Advanced systems. One important approach for CoMP is Joint Transmission (JT). However, the analytical model of JT has not been fully studied, as user equipments (UEs) receiving the desired signals from an adjacent base station (BS) as well as serving BS, or only serving BS were not distinguished. We derive a new analytical model to describe the call admission control in JT based systems. The performance measures of interest are the call blocking probability, and resource utilization. Furthermore, we compare the performance of JT-based systems and non-JT- based systems. The analytical results are in reasonable agreement with the simulation results.

Analytical Study on Free Vibration of Cylindrical Liquid-Storage Tanks (원통형 액체저장탱크의 고유진동에 대한 이론적 연구)

  • Lee, Jin-Kyu;Lee, Sang-Young;Kim, Ki-Whan;Cho, Jin-Rae;Park, Tae-Hak;Lee, Woo-Yong
    • Proceedings of the KSME Conference
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    • 2000.04a
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    • pp.602-607
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    • 2000
  • Fuel-storage tank is a representative example of liquid-structure interaction systems. In order to prevent the undesired structural failure by a variety of external loads, the reliable analysis of the dynamic response of such structural system is of a great importance. In this paper, we address the analytical study on free vibration of axisymmetric cylindrical fuel-storage tanks together with the parametric investigation of eigen-characteristics with respect to the relative fuel fill-height and the relative tank height. Numerical results illustrating theoretical results are also included.

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The Experimental and Analytical Study on the Behavior of Composite Beam in the Processing of External Post Prestressing strengthen (외부 후긴장 보강 과정의 합성보 거동에 대한 실험 및 해석적 연구)

  • Park, Yong-Gul;Park, Young-Hoon
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.5 no.4
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    • pp.147-153
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    • 2001
  • The major objectives of this study are to investigate experimental and analytical behavior of composite steel plate strengthened by external post prestressing method and to study the increasing magnitude of load carrying capacity by the external post prestressing method. With installed strain gauges and LVDT, the change of structural behaviors according to the amount of prestressing force is measured and the effects of shear strengthening according to the degree of angle in tendon are studied. The analytical structural behavior according to the amount of prestressing force is also investigated using finite element method. The effectiveness of strengthening of external post prestressing method is proved and an efficient FEM model is suggested by comparing the test results and analyzing results.

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Electromagnetic Analysis and Control Parameter Estimation of Moving-Coil LOA Using Transfer Relations (전자기적 전달관계를 이용한 가동코일형 LOA의 전자기적 특성해석 및 제어정수 도출)

  • Jang, Seok-Myeong;Choi, Jang-Young;Cho, Han-Wook;Park, Ji-Hoon;Jeong, Sang-Sub
    • Proceedings of the KIEE Conference
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    • 2005.10c
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    • pp.129-131
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    • 2005
  • This paper deals with an electromagnetic analysis and control parameter estimation of a moving-coil linear oscillatory actuator (MCLOA). Analytical solutions for electromagnetic characteristics of the MCLOA are obtained from transfer relations derived in terms of a magnetic vector potential and two-dimensional (2-d) rectangular coordinate systems. And then, on the basis of 2-d analytical solutions, control parameters such as the thrust constant, the back-emf constant and winding inductances are estimated. Finally, analytical results for both electromagnetic characteristics and control parameters of the MCLOA are validated extensively by finite element (FE) analyses. In particular, test results such as static thrust, resistance and inductance measurements are given to confirm the analyses.

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Rotordynamic Analysis and Experiment of Superconducting Magnetic Bearings-Flywheel System (초전도 자기베어링-플리이휠 시스템의 회전체 해서 및 실험)

  • Kim, Jong-Soo;Lee, Soo-Hun
    • Journal of the Korean Society for Precision Engineering
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    • v.16 no.9
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    • pp.104-109
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    • 1999
  • The flywheel energy storage system using superconducting magnetic bearings is a device to store electrical energy as rotatioal kinetic energy by motor and to convert it to electrical energy by generator when it is necessary. The rotordynamic analysis should be performed with an adequate analytical model and equations of motion to identify the stable driving condition and the dynamic behavior. The critical speed and the unbalance response of superconducting magnetic bearings-flywheel system are studied in this paper. The analytical results show that the system has one forward whirling mode and two backward whirling models below 500rpm. The maximum displacement 0.75mm is detected at the first forward mode (385rpm)through unbalance response analysis. The analytical results are compared with the experimental result by the spin-down test. The experimental result shows that the maximum displacement is 0.7mm at 370rpm.

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Flexural and tensile properties of a glass fiber-reinforced ultra-high-strength concrete: an experimental, micromechanical and numerical study

  • Roth, M. Jason;Slawson, Thomas R.;Flores, Omar G.
    • Computers and Concrete
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    • v.7 no.2
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    • pp.169-190
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    • 2010
  • The focus of this research effort was characterization of the flexural and tensile properties of a specific ultra-high-strength, fiber-reinforced concrete material. The material exhibited a mean unconfined compressive strength of approximately 140 MPa and was reinforced with short, randomly distributed alkali resistant glass fibers. As a part of the study, coupled experimental, analytical and numerical investigations were performed. Flexural and direct tension tests were first conducted to experimentally characterize material behavior. Following experimentation, a micromechanically-based analytical model was utilized to calculate the material's tensile failure response, which was compared to the experimental results. Lastly, to investigate the relationship between the tensile failure and flexural response, a numerical analysis of the flexural experiments was performed utilizing the experimentally developed tensile failure function. Results of the experimental, analytical and numerical investigations are presented herein.

Analytical solutions for bending of transversely or axially FG nonlocal beams

  • Nguyen, Ngoc-Tuan;Kim, Nam-Il;Lee, Jaehong
    • Steel and Composite Structures
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    • v.17 no.5
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    • pp.641-665
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    • 2014
  • This paper presents the analytical solutions for the size-dependent static analysis of the functionally graded (FG) beams with various boundary conditions based on the nonlocal continuum model. The nonlocal behavior is described by the differential constitutive model of Eringen, which enables to this model to become effective in the analysis and design of nanostructures. The elastic modulus of beam is assumed to vary through the thickness or longitudinal directions according to the power law. The governing equations are derived by using the nonlocal continuum theory incorporated with Euler-Bernoulli beam theory. The explicit solutions are derived for the static behavior of the transversely or axially FG beams with various boundary conditions. The verification of the model is obtained by comparing the current results with previously published works and a good agreement is observed. Numerical results are presented to show the significance of the nonlocal effect, the material distribution profile, the boundary conditions, and the length of beams on the bending behavior of nonlocal FG beams.

Evaluation of local and global ductility relationships for seismic assessment of regular masonry-infilled reinforced concrete frames using a coefficient-based method

  • Su, R.K.L.;Tang, T.O.;Lee, C.L.
    • Earthquakes and Structures
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    • v.5 no.1
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    • pp.1-22
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    • 2013
  • Soft storey failure mechanism is a common collapse mode for masonry-infilled (MI) reinforced concrete (RC) buildings subjected to severe earthquakes. Simple analytical equations correlating global with local ductility demands are derived from pushover (PO) analyses for seismic assessments of regular MI RC frames, considering the critical interstorey drift ratio, number of storeys and lateral loading configurations. The reliability of the equations is investigated using incremental dynamic analyses for MI RC frames of up to 7 storeys. Using the analytical ductility relationship and a coefficient-based method (CBM), the response spectral accelerations and period shift factors of low-rise MI RC frames are computed. The results are verified through published shake table test results. In general applications, the analytical ductility relationships thus derived can be used to bypass the onerous PO analysis while accurately predicting the local ductility demands for seismic assessment of regular MI RC frames.