• Title/Summary/Keyword: Guideline Structure Analysis

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FEM Analysis of Smart Skin Structure Specimen (스마트 스킨 구조물 시편의 유한요소 해석)

  • 전지훈;황운봉
    • Composites Research
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    • v.16 no.4
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    • pp.59-65
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    • 2003
  • FEM analysis of the smart skin structure, and application of the sandwich structures investigated. The honeycomb manufactures only provide stillness of thickness direction and transverse shear modulus. Although these are dominant mechanical properties. the other mechanical properties are needed in FEM analysis. Hence, this work shows procedures of obtaining those mechanical properties. Honeycomb material was assumed to be ar, isotropic material and properties are estimated by its dominant honeycomb properties. The other honeycomb properties are then obtained by mechanical properties of Nomex. Buckling test and three point bending test were simulated by ABAQUS. Both the shell and solid element models were used. The results were compared with experimental results and analytical approaches. They showed good agreements. This study shows a guideline of FEM analysis of smart skin structure using commercial a FEM package.

Reliability study of CFRP externally bonded concrete beams designed by FIB bulletin 14 considering corrosion effects

  • Dehghani, Hamzeh
    • Advances in concrete construction
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    • v.13 no.2
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    • pp.191-198
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    • 2022
  • FIB is introduced as the sole guideline for the design purpose that results in a practical relationship for the torsional capacity of concrete beams strengthened with carbon fiber-reinforced polymer (CFRP). This study applies first-order reliability method to assess the reliability evaluation of the torsional capacity of CFRP-strengthened beams on the basis of FIB guidelines. In terms of steel reinforcement losses, this study applies a corrosion model to investigate the ceaseless deterioration of the existing structure. Hence, the average of reliability indices varies between 2.68 and 2.80, indicating the reliability viewpoint of the design methodologies. The average values are somehow low compared to the target values of reliability (3.0 or 3.5) applied in the calibration stage of the FIB guideline. In this way, the partial safety factors may change in the forthcoming guideline revisions. For this aim, the reliability of strengthening ratio was applied to assess the variation in the average value of the reliability index with different partial safety factors. The performance of parametric study for the factor proved that minimum values of 1.60 and 2.32 are required for target values of reliability (3.0 and 3.5), respectively.

Seismic Retrofit of Spatial Structures Using Buckling Restrained Brace (비좌굴 가새를 이용한 대공간 구조물 내진 보강 설계)

  • Moon, Hee-Suk;Kim, Gee-Chul;Kang, Joo-Won;Lee, Joon-Ho
    • Journal of Korean Association for Spatial Structures
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    • v.18 no.4
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    • pp.105-111
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    • 2018
  • In this study, the seismic performance and behavior characteristics of the upper truss structure of the large stadium are analyzed by nonlinear dynamic analysis. In the nonlinear dynamic analysis, the earthquake records were generated by site response analysis to simulate the nonlinear behavior of the relevant soil condition where the structure is located. Nonlinear dynamic analysis was performed using Perform-3D and the nonlinear properties of the substructure and the superstructure were determined in accordance with KISTEC guideline. According to the analysis results, excessive deformation occurred in the upper truss element, and plastic hinges exceeded the target performance in some members. Buckling-restrained brace is used for seismic retrofit of stadium structures and the analysis results shows the interstory drift satisfies the target performance level with dissipating the seismic energy efficiently.

A Study on Test Methods for Performance Appraisal of Root Barrier Appling to Green Roofs (옥상 및 인공지반녹화용 방근재의 성능기준 설정을 위한 방근성 시험방법에 관한 연구)

  • Oh, Sang-Keun;Kwak, Kyu-Sung;Sun, Yoon-Suk;Kwon, Shi-Won
    • Journal of the Korea Institute of Building Construction
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    • v.7 no.1 s.23
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    • pp.79-84
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    • 2007
  • Selection of proper root barrier as destination part of greening is very important in Root penetration resistance plan. To select proper root barrier, it need to understand composition of greening part, size, kind of plant, connection with waterproofing layer. In this point of view, we have establish greening on the roof or concrete structure, not been understand the structural mechanism. It means that we misunderstood about purpose of greening and using it. So, chosen materials and construction method was not proper for greening, it caused water leakage and decrease performance of concrete structure. Therefore, we would suggest 5 items of test methods considering environmental condition for green roof. Watertightness by water of greening part, root penetration resistance test by root penetration, bacteria resistance by must or bacteria in soil, chemical resistance by rain and chemical agent of fertilizer, and load resistance by soil depth, size of plant. These suggested test methods could be referred as guideline to test in green roof system because of not exist any performance appraisal guideline or standard. Consequently, it should be analysis as technical and institutional subdividing test methods and it need to study constantly as varied angles.

A Study on the Performance Appraisal for Copper Sheet as Root Barrier Material Appling to Green Roof System (옥상녹화 및 인공지반녹화용 구리시트 방근재의 성능평가에 관한 연구)

  • Cho, Il-Kyu;Kwon, Shi-Won;Kwak, Kyu-Sung;Oh, Sang-Keun
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2007.04a
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    • pp.5-8
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    • 2007
  • Selection of proper root barrier as destination part of greening is very important in Root penetration resistance plan. To select proper root barrier, it need to understand composition of greening part, size, kind of plant, connection with waterproofing layer. In this point of view, we have establish greening on the roof or concrete structure, not been understand the structural mechanism. It means that we misunderstood about purpose of greening and using it. So, chosen materials and construction method was not proper for greening, it caused water leakage and decrease performance of concrete structure. Therefore, we examine the practical use of copper sheet considering environmental condition for green roof. Watertightness by water of greening part, root penetration resistance test by root penetration, bacteria resistance by must or bacteria in soil, chemical resistance by rain and chemical agent of fertilizer, and load resistance by soil depth, sire of plant. These suggested test methods could be referred as guideline to test in green roof system because of not exist any performance appraisal guideline or standard. Consequently, it should be analysis as technical and institutional subdividing test methods and it need to study constantly as varied angles.

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A Suggestion of Contingency Guidelines According to ISDC Based on Overseas Contingency Data

  • Minhee Kim;Chang-Lak Kim;Sanghwa Shin
    • Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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    • v.20 no.4
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    • pp.541-550
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    • 2022
  • When decommissioning nuclear power plant (NPP), the first task performed is cost estimation. This is an important task in terms of securing adequate decommissioning funds and managing the schedule. Therefore, many countries and institutions are conducting continuous research and also developing and using many programs for cost estimation. However, the cost estimated for decommissioning an NPP typically differs from the actual cost incurred in its decommissioning. This is caused by insufficient experience in decommissioning NPPs or lack of decommissioning cost data. This uncertainty in cost estimation can be in general compensated for by applying a contingency. However, reflecting an appropriate standard for the contingency is also difficult. Therefore, in this study, data analysis was conducted based on the contingency guideline suggested by each institution and the actual cost of decommissioning the NPP. Subsequently, TLG Service, Inc.'s process, which recently suggested specific decommissioning costs, was matched with ISDC (International Structure for Decommissioning Costing)'s work breakdown structure (WBS). Based on the matching result, the guideline for applying the contingency for ISDC's WBS Level 1 were presented. This study will be helpful in cost estimation by applying appropriate contingency guidelines in countries or institutions that have no experience in decommissioning NPPs.

Field Test on Rigidities of Piers in High-speed Railway (고속전철 교각의 강성도 산정을 위한 현장실험)

  • 진원종;곽종원;김병석;박성용
    • Proceedings of the Korea Concrete Institute Conference
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    • 2000.10a
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    • pp.745-750
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    • 2000
  • The rigidity of pier is important in the analysis of rail on high speed railway bridges. This study is being performed because of followings. 1) Actual longitudinal stiffness of the structure including substructure should be considered in the calculation of longitudinal stresses in rails. 2) There are many uncertainties in piers and foundations for design. 3) Actual guideline for the design of piers is necessary. 4) Measurement on the rigidity of pier according to the types of pier, foundation and soil-condition is needed. Curve for rigidity will be obtained through this study and applied for actual design as the guideline. Stresses in rails can be estimates accurately. A pair of piers, which consists of pot-bearing for fixed support and pad-bearing for movable support, is loaded by steel frame through steel wire ropes. The responses which are intended to measure in the field test are displacements, forces and tilts on the top of piers.

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Structural Analysis of a Breakwater in Wave and Seismic Loads (파랑하중과 지진하중하의 방파제 구조해석)

  • Cho, Kyu-Nam
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.22 no.1
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    • pp.45-52
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    • 2009
  • In this paper, a guideline for designing breakwater in wave loads and in seismic loads is proposed. A simple model structure in breaking wave zone is examined using Morison equation in consideration with the effect of an impact load, for evaluation of the wave loads. As the impact load effect is not significant, pressure distributions according to Goda are applied for evaluation of wave loads on breakwater. Structural behavior of breakwater in wave loads can be obtained using the Goda method, as well. For seismic analysis, Ofunato and Hachinohe models, as well as an artificial seismic acceleration loads model, are adopted. Soil-structure interaction analysis is carried out to find the seismic load effect. It is found that, in certain cases, structural deformation in wave loads is in the same level as deformation that in seismic loads. Thus, it is our recommendation that these two loads are considered at the same level in breakwater design.

Planning Guidelines for the Superstructure of Floating Architecture (플로팅 건축 상부시설의 계획 지침에 관한 연구)

  • Ko, Min-Chul;Song, Seog-Ki
    • Journal of Navigation and Port Research
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    • v.36 no.3
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    • pp.189-196
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    • 2012
  • Recently constructed several floating buildings, in Korea, provoked the discussion about the activation of floating architecture. But, there is no guideline for the planning of floating architecture in Korea. This study aims to propose the framework of planning guidelines for the superstructure of floating architecture. For the purpose, collected various exiting guidelines related to floating architecture, and then analysed the structure and components of those guidelines. As a result of analysis, many components, could be used as references, are extracted. After the classification of the components into several categories, then, compared the content of components, derived from different guidelines, in same category. Based on the former analysis and comparison, proposed the framework of planning guidelines for the superstructure of floating architecture, consist of various set of components.

Contact Analysis on a Born-Holder Assembly for Wire Bonding (와이어 본더용 Horn-Holder Assembly의 접촉 해석)

  • Jang, Chang-Soo;Ahn, Geun-Sik;Kim, Young-Joon;Kwak, Dong-Ok;Boo, Seong-Woon
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.26 no.10
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    • pp.2008-2017
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    • 2002
  • Joint structure of a transducer horn-holder assembly fur a wire bonder was examined through FEM contact analysis. A three dimensional modeling and analysis was carried out to survey the internal physics of this structure and to prove the accuracy of a computation compared to a measurement. After validation, a simple two dimensional model was built fur various parametric study considering the efficiency and speed of the computation. Several factors such as boundary conditions, a modeling boundary, mesh density and so on, were considered to obtain consistency with three dimensional analysis. An arc angle and a position of each holder boss were chosen as design parameters. A design of experiment was applied to find out an optimized design of the holder geometry. As a result, a guideline for holder boss design was suggested and main factors and their influence on stress concentration in the transducer horn were surveyed.