• 제목/요약/키워드: Limit displacement

검색결과 357건 처리시간 0.028초

Three-dimensional simplified slope stability analysis by hybrid-type penalty method

  • Yamaguchi, Kiyomichi;Takeuchi, Norio;Hamasaki, Eisaku
    • Geomechanics and Engineering
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    • 제15권4호
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    • pp.947-955
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    • 2018
  • In this study, we propose a three-dimensional simplified slope stability analysis using a hybrid-type penalty method (HPM). In this method, a solid element obtained by the HPM is applied to a column that divides the slope into a lattice. Therefore, it can obtain a safety factor in the same way as simplified methods on the slip surface. Furthermore, it can obtain results (displacement and strain) that cannot be obtained by conventional limit equilibrium methods such as the Hovland method. The continuity condition of displacement between adjacent columns and between elements for each depth is considered to incorporate a penalty function and the relative displacement. For a slip surface between the bottom surface and the boundary condition to express the slip of slope, we introduce a penalty function based on the Mohr-Coulomb failure criterion. To compute the state of the slip surface, an r-min method is used in the load incremental method. Using the result of the simple three-dimensional slope stability analysis, we obtain a safety factor that is the same as the conventional method. Furthermore, the movement of the slope was calculated quantitatively and qualitatively because the displacement and strain of each element are obtained.

개선된 참조응력법을 이용한 복합균열이 존재하는 배관의 균열개구변위 계산 (Crack Opening Displacement Analysis of Complex Cracked Pipes based on Enhanced Reference Stress Method)

  • 허남수;김윤재;김영진
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2001년도 추계학술대회논문집A
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    • pp.80-86
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    • 2001
  • An engineering estimation equation for the crack opening displacement (COD) is proposed for a complex cracked pipe, based on the reference stress approach. To define the reference stress, a simple plastic limit load analysis for the complex cracked pipe subjected to combined bending and tension is performed considering the crack closure effect in the compressive-stressed region. Comparison with ten published test data and the results from existing method shows that the present method not only reduces non-conservatism associated with the existing method, but also provides consistent and overall satisfactory results.

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복합균열이 존재하는 배관의 균열개구변위 계산을 위한 새로운 공학적 계산식 (New Engineering Approach for Estimating Crack Opening Displacement of Complex Cracked Pipes)

  • 김영진;허남수;김윤재
    • 대한기계학회논문집A
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    • 제25권8호
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    • pp.1235-1241
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    • 2001
  • An engineering estimation equation for the crack opening displacement(COD) is proposed for a complex cracked pipe, based on the reference stress approach. To define the reference stress, a simple plastic limit load analysis for the complex cracked pipe subjected to combined bending and tension is performed considering the crack closure effect in the compressive-stressed region. Comparison with ten published test data and the results from existing method shows that the present method not only reduces non-conservatism associated with the existing method, but also provides consistent and overall satisfactory results.

이중 아웃리거 구조 시스템의 한계 세장비에 대한 연구 (Study on the Limit Slenderness of a Double Outrigger System)

  • 양재광;강호근;박성수
    • 대한건축학회논문집:구조계
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    • 제34권3호
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    • pp.11-18
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    • 2018
  • Due to the recent overpopulation of urban cities, land shortage and soaring land prices have caused an increase in the demand for high-rise buildings. To build buildings on a limited land, the size of the building is important. Displacement control by horizontal loads in a skyscraper is critical to securing stability and usability of structures. Several systems have been proposed for efficient horizontal displacement control, and so far the study continues. Among them, the Outrigger System is a representative of the typical horizontal load resistance system. Although studies have been conducted so far to locate the optimal position of the outrigger, studies of the slenderness ratio of the buildings are still insufficient. Based on the Outrigger-Optimized Position equation, this study induces the calculation of the displacement of the outrigger installation building according to the slenderness ratio.

인공지능 기법을 활용한 건축 구조물 변위측정시스템 개발 (Development of a displacement measurement system for architectural structures using artificial intelligence techniques)

  • 강예진;김대건;우종열;이동운
    • 한국건축시공학회:학술대회논문집
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    • 한국건축시공학회 2022년도 봄 학술논문 발표대회
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    • pp.135-136
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    • 2022
  • As a recent technology, it is possible to partially grasp the occurrence of displacement of the entire building through artificial intelligence technology for big data through scanning. However, scanning and data processing take a lot of time, so there is a limit to constant monitoring, so constant monitoring technology of building behavior that combines wireless remote sensors and 3D shape scanning is required. Therefore, in this study, artificial intelligence program coding technology is linked. In addition, a technology capable of real-time wireless remote measurement of structure displacement will be developed through technology development in response to safety management that combines existing building technologies such as sensors. Through this, it is possible to establish an integrated management system for safety inspection and diagnosis.

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진동사용성을 고려한 철도교량구조물의 강성한계 분석 (Estimation of Stiffness Limit for Railway Bridge Vibration Serviceability)

  • 전법규;김남식;김성일
    • 한국철도학회논문집
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    • 제11권5호
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    • pp.489-498
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    • 2008
  • 일반적으로 허용처짐 기준은 정적 사용성과 구조적안전성에 그 기반을 두고 있으며 진동사용성에 대한 고려는 부족하다. 따라서 진동사용성을 고려할 수 있는 교량의 허용처짐 기준이 필요하다고 판단된다. 본 논문에서는, 한국철도교설계기준의 허용처짐기준을 주파수영역의 진동사용성 기준과 비교하였으며, 프랑스 및 일본의 철도교설계기준의 진동사용성 허용기준 또한 분석하였다. 그 결과, 한국철도교설계기준의 경우 열차의 속도에 따른 기준으로 진동지속시간이 부분적으로 고려되었지만 진동사용성은 만족하지 못하고 있는 것으로 판단되었으며, 국외 철도교설계기준비 분석결과, 진동사용성을 고려한 허용처짐기준을 제시할 수 있을 것으로 판단하였다. 공용중인 철도교량의 진동사용성을 평가하기위하여 다양한 형식의 철도교량의 진동신호를 측정하였다. 그리고, 현장에서 적용하기 편리한 진동사용성 처짐 및 강성한계를 제시하기 위하여 공용중인 교량을 대상으로 차량 교량 상호작용해석을 수행하였다.

Linear elastic and limit state solutions of beam string structures by the Ritz-method

  • Xue, Weichen;Liu, Sheng
    • Structural Engineering and Mechanics
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    • 제35권1호
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    • pp.67-82
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    • 2010
  • The beam string structure (BSS) has been widely applied in large span roof structures, while no analytical solutions of BSS were derived for it in the existing literature. In the first part of this paper, calculation formulas of displacement and internal forces were obtained by the Ritz-method for the most commonly used arc-shaped BSS under the vertical uniformly distributed load and the prestressing force. Then, the failure mode of BSS was proposed based on the static equilibrium. On condition the structural stability was reliable, BSS under the uniformly distributed load would fail by tensile strength failure of the string, and the beam remained in the elastic or semi-plastic range. On this basis, the limit load of BSS was given in virtue of the elastic solutions. In order to verify the linear elastic and limit state solutions proposed in this paper, three BSS modal were tested and the corresponding elastoplastic large deformation analysis was performed by the ANSYS program. The proposed failure mode of BSS was proved to be correct, and the analytical results for the linear elastic and limit state were in good agreement with the experimental and FEM results.

J and CTOD Estimation for Homogeneous and Bi-Material Fracture Toughness Testing Specimens

  • Lee, Hyungyil;Kim, Yun-Jae
    • Journal of Mechanical Science and Technology
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    • 제15권8호
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    • pp.1079-1089
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    • 2001
  • This paper proposes J and CTOD estimation schemes applied to fracture toughness testing, covering typical homogeneous and bi-material specimens. Recommendations are based on the plastic limit analysis (either slip line field or finite element limit analyses), assuming the rigid plastic material behavior. The main outcome of the present study is that the J and CTOD estimation schemes (both codified and non-codified), recommended for homogeneous specimens, can be equally used for bi-material specimens with interface cracks. The effect of yield strength mismatch in bi-material specimens on the J-integral CTOD is discussed.

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Failure analysis of ribbed cross-laminated timber plates

  • Lavrencic, Marko;Brank, Bostjan
    • Coupled systems mechanics
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    • 제7권1호
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    • pp.79-93
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    • 2018
  • The process of material failure i.e. cracks development and their propagation in an experiment related to the bending collapse of cross laminated timber plate with ribs is described. Numerical simulation of such an experiment by the nonlinear finite element method is presented. The numerical model is based on Hashin failure criteria, initially developed for unidirectional composites, and on material softening concept applied by the smeared crack approach. It is shown that such a numerical model can be used for an estimation of the limit load and the limit displacement of a cross laminated timber ribbed plate.

LRB 면진장치를 적용한 원전구조물의 지진응답에 따른 확률론적 연구 (A Probabilistic Study on Seismic Response of Seismically Isolated Nuclear Power Plant Structures using Lead Rubber Bearing)

  • 김현정;송종걸;문지호
    • 한국지진공학회논문집
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    • 제22권2호
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    • pp.45-54
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    • 2018
  • The seismically isolated nuclear power plants shall be designed for design basis earthquake (DBE) and considered to ensure safety against beyond design basis earthquake (BDBE). In order to limit the excessive displacement of the seismic isolation system of the seismically isolated structure, the moat is installed at a certain distance from the upper mat supporting the superstructure. This certain distance is called clearance to stop (CS) and is calculated from the 90th percentile displacement of seismic isolation system subjected to BDBE. For design purposes, the CS can be obtained simply by multiplying the median displacement of the seismic isolation system against DBE by scale factor with a value of 3. The DBE and BDBE used in this study were generated by using 30 sets of artificial earthquakes corresponding to the nuclear standard design spectrum. In addition, latin hyper cube sampling was applied to generate 30 sets of artificial earthquakes corresponding to maximum - minimum spectra. For the DBE, the median displacement and the 99th percentile displacement of the seismic isolation system were calculated. For the BDBE, the suitability of the scale factor was assessed after calculating the 90th percentile displacement of the seismic isolation system.