• Title/Summary/Keyword: 강 진단모델

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A study of seasonal variation of the residual flow before and after Saemangeum reclamation (새만금간척 전.후 잔차류의 계절변화에 관한 연구)

  • Shin, Moon-Seup;vanagi, T.;Hong, Sung-Kun;Lee, Dong-Ju
    • Journal of Korea Water Resources Association
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    • v.35 no.4 s.129
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    • pp.425-442
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    • 2002
  • The land reclamation area of Saemangeum(Kunsan) is located between $126^{\circ}10'\;E{\sim}126^{\circ}50'\;E\;and\;35^{\circ}35'\;N{\sim}36^{\circ}05'\;N$ at the western coast of the Korean peninsula. The reclamation area of Saemangeum has a range of 5.6m spring tide and the maximum tidal current speed is about $1.41m\;s^{-1}$. In ordinary spring tide. Most of the sediments deposited on the tidal flats are transported from the Geum river, the Mankyung river and the Dongjin river. The soil in this area consists of silty sand with the depth of 10m to 30m. The wind in winter is strong from the direction of northwest. Saemangeum coastal area is being constructed 33km the sea dike and 40,100ha reclamation area. The purpose of this study Is to find the residual circulations in four seasons before and after the dike construction by a robust diagnostic and prognostic numerical model.

Damage Curves of the Fixed Ends Beam with the Rigid-Plastic Model (강-소성 모델을 이용한 양단 고정보의 손상곡선)

  • Kim, Seok Ki
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.8 no.4
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    • pp.239-246
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    • 2004
  • The fixed ends beam is analyzed by the s d 0 f system with the rigid-plastic model. And the safety criteria of the fixed ends beam to the Impulsive loads are established with the peak-load ratio to the static collapse load and impulse ratio to the ideal impulse producing the critical displacement. It is shown that the impulse and the peak-load of the impulsive loads are the important factors for the damage of the structures. It is also shown that the damage curves with the peak-load and impulse ratio are useful method to estimate the damage of the structures due to the emphasis on the equivalent dynamic loads rather than the equivalent static loads in the process of deriving the curve.

Evaluation of the Seismic Performance for Domestic URM Buildings Using Nonlinear Dynamic Analysis (비선형 동적해석을 통한 국내 비보강 조적조 건축물의 내진성능 평가)

  • Baek, Eun-Rim;Kim, Jung-Hyun;Lee, Sang-Ho
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.20 no.3
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    • pp.83-92
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    • 2016
  • The purpose of this study is to evaluate the seismic performance of domestic unreinforced masonry(URM) buildings using nonlinear dynamic analysis. For that, the nonlinear hysteresis models suggested in the previous research were validated for the dynamic analysis. The results of the shaking table test were compared with the dynamic analysis results using the suggested nonlinear hysteresis models. As a result, the nonlinear hysteresis models were expected to be applicable to the dynamic analysis of URM buildings. Based on the models, the dynamic analysis of domestic URM buildings varying the number of stories and opening ratio was carried out. The analysis results showed that most of the domestic URM buildings were very vulnerable to design earthquake in Korea.

Numerical Study on Columns Subjected to Blast Load Considering Compressive Behavior of Steel Fiber Reinforced Concrete (강섬유보강콘크리트의 압축거동 특성을 반영한 기둥의 내폭해석 )

  • Jae-Min Kim;Sang-Hoon Lee;Jae Hyun Kim;Kang Su Kim
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.27 no.5
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    • pp.105-112
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    • 2023
  • Steel fiber reinforced concrete (SFRC) exhibits enhanced strength and superior energy dissipation capacity compared to normal concrete, and it can also reduce crack propagation and fragmentation of concrete even when subjected to blast loads. In this study, the parameters defining failure surface and damage function of the K&C concrete nonlinear model were proposed to be applied for the properties of SFRC in LS-DYNA. Single element analysis has been conducted to validate the proposed parameters in the K&C model, which provided very close simulations on the compressive behavior of SFRC. In addition, blast analysis was performed on SFRC columns with different volume fractions of steel fibers, and the blast resistance of SFRC columns was quantitatively analyzed with Korea Occupational Safety & Health Agency (KOSHA) guidelines.

An Experimental Study on the Temperature Difference between the Top and Bottom Flange in Steel Girder without Concrete Slab (콘크리트 슬래브가 없는 강재주형에서 상하연 온도차에 대한 실측연구)

  • Shin, Dong-Wook;Kim, Kyoung-Nam;Jung, Kyoung-Sup;Lee, Seong-Haeng
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.18 no.4
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    • pp.99-106
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    • 2014
  • In order to study the reasonable design thermal loads, the steel box girder bridge specimen which have no concrete slab was manufactured with the real size dimension. The temperature data were measured for 5 month at the 18 thermo gauges which were attached according to height. The temperature differences between the top and bottom flange in steel box girder specimen were calculated and the temperature gradient models were proposed by the probabilistic method. This proposed model showed a correlation of approximately 97% when compared with the similar model of Euro Code. Thus, the temperature gradient models which were suggested in this study may be used as the basis data in calculating the design load temperature.

Design of Rigid Joints Using Strut-Tie Model (스터럿-타이 모델에 의한 강절점 영역설계에 관한 연구)

  • Won, Dae-Yon
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.18 no.1
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    • pp.31-39
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    • 2014
  • In order to design rigid zone area of frame structures, it is important to predict the direction change of internal stresses according to the bending moment acting on the joint region. In this study, it was examined whether current highway bridge design standards are useful to design different types of rigid joints having a various haunch shapes. In addition, stress distributions of inside of various rigid joints were inspected using the linear elastic finite element analysis. Based on the results of finite element analysis, the strut-tie models to design rigid joints are proposed. Suggested by this study, the strut-tie models have a same level of accuracy to a linear elastic finite element analysis. The proposed strut-tie models will be useful to design reinforcement details of rigid joints having a various haunch types.

Nonlinear Analysis Model Considering Failure Mode of Unreinforced Masonry Wall (파괴모드를 고려한 비보강 조적벽체의 비선형 해석모델)

  • Baek, Eun-Lim;Kim, Jung-Hyun;Lee, Sang-Ho;Oh, Sang-Hoon
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.18 no.4
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    • pp.33-40
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    • 2014
  • The final purpose of this study is to evaluate the seismic performance of unreinforced masonry (URM) building more accurately. For that, shear strength and hysteresis model considering failure mode of the URM wall were discussed. The shear strength of URM wall without openings could be calculated by determining on the minimum value between the rocking strength suggested by domestic research and the sliding strength suggested by FEMA. The wall having openings could be predicted properly by the FEMA method. And the nonlinear hysteresis models for flexural and shear behaviors considering failure mode were proposed. As the result of the nonlinear cyclic analysis that carried out using suggested models, these analysis models were proper to represent the seismic behavior of URM walls.

Evaluation of Flexural Strength and Ductility of Hybrid Fiber Reinforced UHSC Flexural Members (하이브리드 강섬유 보강 초고강도 콘크리트 휨파괴형 부재의 강도 및 연성 평가에 관한 연구)

  • Yuh, Ok-Kyung;Bae, Baek-Il
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.23 no.6
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    • pp.61-69
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    • 2019
  • In this study, the flexural strength and curvature ductility factor of single and hybrid fiber reinforced ultra high strength concrete flexural members with conventional steel rebar were evaluated by experimental program with 3-UHSC beams. Test specimens were loaded by 4-pointed flexural loading. According to the test results, hybrid fiber reinforced UHPC test specimens had higher moment resisting capacity and ductility. For the safe design of hybrid fiber reinforced UHPC, test specimens were analyzed according to the sectional analysis method with material models suggested by K-UHPC design recommendation. Current K-UHPC design recommendation predict the moment resisting capacity of member conventionally and over-estimated the ductility.

Development of Multi-scale Model for Concrete Strength Estimation using Intelligent Self-diagnostic sensor (지능형 자가진단센서를 이용한 콘크리트 강도추정을 위한 다중스케일모델 개발)

  • Kim, Dong-Jin;Park, Woong-Ki;Lee, Chang-Gil;Hong, Seok-Inn;Park, Seung-Hee
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 2011.04a
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    • pp.303-306
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    • 2011
  • 본 논문은 콘크리트의 양생 강도 발현을 모니터링하기 위하여 매립형 압전 센서를 이용하여 콘크리트 내부의 임피던스 및 유도초음파 신호를 측정함으로써, 콘크리트의 양생 강도를 실시간 추정할 수 있는 기법을 개발하였다. 임피던스 및 유도초음파 신호는 구조물의 물성을 나타내며 특히 양생 기간 중 임피던스 및 유도초음파의 변화는 해당 콘크리트 구조물의 강도변화를 나타낼 수 있다. 이를 이용하여 매립형 압전 센서로부터 저비용의 셀프 센싱 기반 임피던스 및 유도초음파를 계측하여 콘크리트의 임피던스 공진 주파수 및 유도초음파의 전달 강도를 측정하고 측정된 신호를 통하여 콘크리트 양생 강도를 추정할 수 있게 된다. 제안된 기법의 적용가능성을 검증하기 위하여 설계 압축강도 30MPa의 콘크리트 슬라브 내부에 매립형 압전 센서를 매립하고 양생기간 동안 임피던스 및 유도초음파 신호를 측정, 비교 분석 하였다. 측정된 신호 및 압축강도를 통하여 임피던스 및 유도초음파 기반 강도 추정 모델을 도출하고 보다 높은 정확도를 얻기 위해 다중스케일 강도 추정 모델을 개발하였다. 결과적으로 본 연구를 통해 매립형 압전 센서를 이용하여 콘크리트의 양생 강도를 실시간 모니터링할 수 있음이 검증되었다.

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