• Title/Summary/Keyword: 변형장

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Shear Deterioration of Reinforced Concrete Beams Failing in Shear after Flexural Yielding (휨항복 후 전단 파괴하는 철근콘크리트 보의 전단성능 저하에 관한 연구)

  • 이정윤
    • Journal of the Korea Concrete Institute
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    • v.13 no.5
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    • pp.466-475
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    • 2001
  • The potential shear strength of reinforced concrete beams decreases after flexural yielding due to the decrease of the effective compressive strength of concrete in plastic hinge zone. A truss model considering shear deterioration in the plastic hinge zone was proposed in order to evaluate the ductile capacity of reinforced concrete beams failing in shear after flexural yielding This model can determine the potential shear strength of the beam by using a truss model. The potential shear strength gradually decreases as the increase of the axial strain of member. When the calculated potential shear strength decreases up to the flexural yielding strength, the corresponding rotation angle is defined as the ductile capacity of the beam. The predicted ductile capacity of reinforced concrete beams is shown to be in a good agreement with experimental results.

The Mechanism of Load Resistance and Deformability of Reinforced Concrete Coupling Beams (철근 콘크리트 연결보의 하중 전달 기구와 변형 능력)

  • Hong, Sung-Gul;Jang, Sang-Ki
    • Journal of the Earthquake Engineering Society of Korea
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    • v.10 no.3 s.49
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    • pp.113-123
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    • 2006
  • An experimental investigation on the behavior of reinforced concrete coupling beams is presented. The test variables are the span-to-depth ratio, the ratio of flexural reinforcements and the ratio of shear rebars. The distribution of arch action and truss action which compose the mechanism of shear resistance is discussed. The increase of plastic deformation after yielding transforms the shear transfer by arch action into by truss action. This study proposes the deformation model for reinforced concrete coupling beams considering the bond slip of flexural reinforcement. The strain distribution model of shear reinforcements and flexural reinforcements based on test results is presented. The yielding of flexural reinforcements determines yielding states and the ultimate states of reinforced concrete coupling beam are defined as the ultimate compressive strain of struts and the degradation of compressive strength due to principal tensile strain of struts. The flexural-shear failure mechanism determines the ultimate state of RC coupling beams. It is expected that this model can be applied to displacement-based design methods.

특집: 미래주도형 성형공정과 수치 해석기술 - 전자기 성형과 수치 해석 기술

  • Kim, Dae-Yong;Kim, Ji-Hun
    • 기계와재료
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    • v.23 no.3
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    • pp.30-47
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    • 2011
  • 전자기 성형 공정은 강한 전이 자기장을 가공하고자 하는 금속에 직접 작용시켜 금속을 변형시키는 가공 기술로 최근 난성형성 소재의 성형 및 이종 소재의 접합 등에 장점을 가지고 있어 관심이 높아지고 있다. 또한, 전자기 성형 공정을 기존의 스템핑, 하이드로포밍과 같은 성형 공정의 단점을 보완하는 공정으로 이용하여 자동차 부품에 적용하려는 연구가 시도되고 있다. 전기, 자기, 열, 변형을 포함하는 복잡한 물리 현상이 관련되어 있는 전자기 성형 공정을 모사하기 위해서 각 물리 현상들을 연계하여 수치적으로 계산해 내는 기술에 대한 연구가 다각도로 진행 중이다. 본 고에서는 전자기 성형 기술에 대한 개념과 최신 국내외 기술 동향을 소개한 후, 전자기 성형의 수치 해석 기술에 대한 연구 동향을 정리하였다.

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Function Regression algorithm (함수모형 회귀분석 및 알고리즘)

  • Kim, Seok Jun;Jang, Geun Ho;Kim, Ye Ji
    • Proceedings of the Korea Information Processing Society Conference
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    • 2017.11a
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    • pp.770-773
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    • 2017
  • Linear Regression 문제를 토대로 변형하여 선형회귀분석, 2차함수모형 회귀분석, '단조 증가(감소)' 3차 함수 모형 회귀분석과 그에 따라 변형되는 gradient descent 알고리즘을 기술한다.

Analysis of Vibration Characteristics of Railway System using the Viscoelastic Materials for Vibration Isolation (점탄성 방진재를 이용한 레일시스템의 진동특성 해석)

  • 이정학;장한기;김광준
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 1993.10a
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    • pp.191-196
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    • 1993
  • 본 연구에서는 이러한 방진궤도의 성능을 파악하고 또 적절한 방진궤도의 설계를 위하여 먼저 모형화하는 방법을 제시하였다. 이를 위해서는 궤도를 구성하는 방진요소의 특성을 결정하는 것이 필수적이므로 현재 사용되고 있 는 점탄성 방진재에 대하여 주파수, 온도, 초기 변형률, 동적변형률등 여러가 지 인자에 대한 물성치를 구하였으며, 이를 이용하여 궤도계의 진동전달 특 성을 파악하고 고찰하였다.

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Long-Term Measurement of Static Strains of Jacket Type Offshore Structure under Severe Tidal Current Environments (빠른 조류 환경에서의 재킷식 해양구조물 시공 중 및 운영 중 장기 변형률 계측 및 분석)

  • Yi, Jin-Hak;Park, Jin-Soon;Park, Jun-Seok;Lee, Kwang-Soo
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.32 no.6A
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    • pp.389-398
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    • 2012
  • In this study, structural strain responses of the jacket-type Uldolmok tidal current power plant structure under severe tidal environments were measured and analyzed using long-term measurement system during construction and also operation. It was observed that there were significant changes in strain responses at the steps of jacket lifting, block loading, pile ejection and insertion. Strains due to dead loads and tidal loads were analyzed before and after removal of a jacket leg, and it was also found that the strains due to dead load were much significantly changed after jacket leg removal. From the measurement data during operation, it was found that strain responses were fluctuated with M2 and M4 tidal periods and also relatively short period of about 10 min due to the peculiar tidal characteristics in the Uldolmok strait. Finally, the neural network-based non-parametric estimation models were investigated to build up the signal-based structural damage monitoring system.

Analytical Study on Characteristics of von Mises Yield Criterion under Plane Strain Condition (평면변형률상태에서의 von Mises 항복기준의 특성에 관한 이론적 연구)

  • Lee, Seung-Hyun;Kim, Byoung-Il
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.16 no.9
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    • pp.6391-6396
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    • 2015
  • In order to investigate characteristics of the von Mises yield criterion under 2 dimensional stress condition, two cases of plane strain were studied. One of which was for zero elastic strain and the other was for zero plastic strain increment. Yield functions for the plane strain condition for zero elastic strain and for the plane stress condition were represented as ellipse and the two yield functions were compared by ratios of major axis, minor axis and eccentricity and it was seen that the ratio of minor axis was the same between the two cases and the ratios of major axis and eccentricity were functions of Poisson's ratio. Region of elastic behavior obtained from considering plane strain condition of zero elastic strain increases as the Poisson's ratio increases. Yield function for plane strain obtained from considering zero plastic increment and associate flow rule was displayed as straight line and the region of elastic behavior was greater than that for the case of plane stress.

Optimized Construction and Visualization of GPU-based Adaptive and Continuous Signed Distance Field, and Its Applications (GPU기반 적응형 및 연속적인 부호 거리장의 최적화된 구성과 시각화, 그리고 그 응용 사례)

  • Moon, Seong-Hyeok;Kim, Jong-Hyun
    • Proceedings of the Korean Society of Computer Information Conference
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    • 2021.07a
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    • pp.655-658
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    • 2021
  • 본 논문에서는 GPU 아키텍처를 이용하여 적응형 부호 거리장을 최적화하여 빠르게 구축하고 시각화 할 수 있는 방법에 대해 제안한다. 쿼드트리를 효율적으로 GPU 메모리로 전달하고, 이를 활용하여 삼각형에 대해 유클리디안 거리를 각 스레드 별로 병렬처리하여 최단 거리를 찾는다. 이 과정에서 GPU를 사용하여 삼각형으로 구성된 3D 메쉬로부터 빠르게 적응형 부호 거리장을 계산할 수 있는 최적화 기법과 절단면 보기, 특정 위치의 값 조회, 실시간 레이트레이싱 및 충돌처리 작업을 빠르고 효율적으로 수행할 수 있는지를 보여준다. 또한, 제안하는 프레임워크를 활용하면 하이 폴리곤 메쉬도 1초 내외로 부호 거리장을 계산할 수 있기 때문에 강체뿐만 아니라 변형체에도 충분히 활용될 수 있다.

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