• Title/Summary/Keyword: 모드응력합성법

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Calculation of Dynamic Stress Time History of a Component Using Computer Simulation (컴퓨터 시뮬레이션을 이용한 동응력 이력 계산기술 개발)

  • 박찬종;박태원
    • Journal of the Korean Society for Precision Engineering
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    • v.17 no.1
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    • pp.52-60
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    • 2000
  • In order to design a reliable machine component efficiently, it is necessary to set up the process of durability analysis using computer simulation technique. In this paper, two methods for dynamic stress calculation, which are basis of durability analysis, are reviewed. Then, a user-oriented dynamic stress analysis program is developed from these two algorithms together with a general-purpose flexible body dynamic analysis and structural analysis programs. Finally, a slider-crank mechanism which has a flexible connecting-rod is chosen to show the special characteristics of these two dynamic stress calculation methods.

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Probabilistic Risk Assessment of a Steel Composite Hybrid Cable-Stayed Bridge Based on the Optimal Reliabilities (최적신뢰성에 의한 강합성 복합사장교의 확률적 위험도평가)

  • Yoon, Jung Hyun;Cho, Hyo Nam
    • Journal of Korean Society of Steel Construction
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    • v.19 no.4
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    • pp.395-402
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    • 2007
  • Probabilistic risk assessment was conducted on a hybrid cable-stayed bridge consisting of a steel-composite plate girder and a concrete girder with a long span, designed using the working stress design and strength design methods. The component reliabilities of the bridge's cables, pylons, girders, and steel-concrete conjunction were evaluated using the AFOSM(Advanced First Order Second Moment) algorithm and the simulation technique at the critical sections, based on the maximum axial force, shear, and positive and negative moments of the selected sections. For the analysis of system reliability, the hybrid cable-stayed bridge consisting of cables, pylons, and plate girders was modeled into combined failure modes, and for system reliability, the probabilities of failure and reliability index of the structural system were evaluated. Based on the results of this study, the critical failure modes of the hybrid cable-stayed bridge based on the bridge's structural characteristics are suggested, and the efficiency of the partial ETA technique for use in the risk assessment method was confirmed.

The suggestion of Steel Plate-Concrete Composite Beam Shape with Bolts (볼트 체결형 강판-콘크리트 합성보의 형상 제안)

  • Cho, Tae-Gu;Choi, Byong-Jeong
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.19 no.7
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    • pp.305-314
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    • 2018
  • The steel-plate concrete composite beam is composed of a steel plate, concrete and a shear connector to combine the two inhomogeneous materials. In general, the steel plate is assembled by welding an existing composite beam. In this study, a new steel-plate concrete composite (SPCC) beam was developed to reduce the size of the shear connector and improve its workability. The SPCC beam was composed of folded steel plates and concrete, without any shear connector. The folded steel plate was assembled with high strength bolts instead of welding. To improve the workability in field construction, a hat-shaped cap was attached in the junction with the slab. Monotonic two-point load testing was conducted under displacement control mode. The flexural strength of the SPCC beam specimen was calculated to be 76% of that of the complete composite beam by using the plastic stress distribution method and strain compatibility method. The cap acted as the stud and accessory. The synthesis rate could be increased by controlling the gap of the cap, and the bending performance could be evaluated by using the strain fitting method considering the synthesis rate of the SPCC beam.

Flexural Strength Evaluation of Steel Plate-Concrete Composite Beam using Bolted (절곡 강판을 볼트로 체결한 강판-콘크리트 합성보의 휨강도 평가)

  • Han, Myoung-Hwan;Choi, Byong-Jeong
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.19 no.6
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    • pp.126-136
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    • 2018
  • A steel-plate concrete composite beam is composed of a steel plate, concrete and shear connector to combine inhomogeneous two materials. The steel plate is assembled by welding an existing composite beam. In this study, new steel-plate concrete composite beam, called a SPC Beam, was developed to reduce the shear connector and improve the workability. The SPC Beam was composed of folding steel plates and concrete, without a shear connector. The folding steel plate was assembled using high strength bolt instead of welding. To improve the workability in field construction, a hat-shaped Cap was attached to the junction with a slab. Monotonic load testing under two points was conducted under displacement control mode. The flexural strength of the specimen for positive moment and negative moment was calculated using the plastic stress distribution method. The test results showed that the flexural strength of the new SPC Beam had 80% of the strength of a complete composite beam. In addition, increasing the composite ratio was possible through clearance controls of the cap. In this study, the performance of the SPC Beam was verified through additional experiments and analyses with the cross-sectional shape and cap as variables, because the representative shape in the positive negative moment region is targeted.