• Title/Summary/Keyword: 기준강도

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Reforming Method and Proposal for the Technical Regulation of Extremely Electric Filed Strength Radio Equipment below 135kHz (135kHz 이하 미약 전계강도 무선기기 기술기준 개선 방안 및 제안)

  • Kim, Sun-Youb;Jeoung, Chan-Gwoun;Kang, Young-Jin
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.14 no.1
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    • pp.9-15
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    • 2010
  • This paper analyzed the problems of the Korean output regulation in the relevant band through an analytic comparison of the current trend of each country and their standard values concerning electric field strength (technical standard) of weak wireless stations with less than 135kHz. In connection with the standard value of electric field strength of each country, which has been proposed in the registration of the appropriate electric wave, the paper aims to propose the standard value of electric field strength that could actually be introduced for suitable unauthorized wireless devices (weak wireless devices) in Korea. Provided that the Korean standard may be upgraded based on the tolerances of electric field strength proposed m this paper, this is expected to be committed to the distribution and advancement of weak wireless devices; and further it is anticipated to be prepared with competitiveness not only in the Korean communications market, but also in the international communications market.

Strut-Tie Models and Load Distribution Ratios for Reinforced Concrete Beams with Shear Span-to-Effective Depth Ratio of Less than 3 (II) Validity Evaluation (전단경간비가 3 이하인 철근콘크리트 보의 스트럿-타이 모델 및 하중분배율(II) 타당성 평가)

  • Chae, Hyun-Soo;Yun, Young Mook
    • Journal of the Korea Concrete Institute
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    • v.28 no.3
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    • pp.267-278
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    • 2016
  • In this study, the ultimate strength of 335 simply supported reinforced concrete beams with shear span-to-effective depth ratio of less than 3 was evaluated by the ACI 318-14's strut-tie model approach implemented with the indeterminate strut-tie models and load distribution ratios of the companion paper. The ultimate strength of the beams was also estimated by using the experimental shear strength models, the theoretical shear strength models, and the current strut-tie model design codes. The validity of the proposed strut-tie models and load distribution ratios was examined by comparing the strength analysis results classified according to the prime design variables of the shear span-to-effective depth ratio, flexural reinforcement ratio, and compressive strength of concrete.

Compressive Stress Distribution of Concrete for Performance-Based Design Code (성능 중심 설계기준을 위한 콘크리트 압축응력 분포)

  • Lee, Jae-Hoon;Lim, Kang-Sup;Hwang, Do-Kyu
    • Journal of the Korea Concrete Institute
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    • v.23 no.3
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    • pp.365-376
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    • 2011
  • The current Concrete Structural Design Code (2007) prescribe the equivalent rectangular stress block of the ACI 318 Building Code as concrete compressive stress distribution for design of concrete structures. The rectangular stress block may be enough for flexural strength calculation, but realistic stress-strain relationship is required for performance verification at selected limit state in performance-based design. Moreover, the ACI rectangular stress block provides non-conservative flexural strength for high strength concrete columns. Therefore a new stress distribution model is required for development of performance-based design code. This paper proposes a concrete compressive stress-strain distribution model for design and performance verification. The proposed model has a parabolic-rectangular shape, which is adopted by Eurocode 2 and Japanese Code (JSCE). It was developed by investigation of experimental test results conducted by the authors and other researchers. The test results cover high strength concrete as well as normal strength concrete. The stress distribution parameters of the proposed models are compared to those of the ACI 318 Building Code, Eurocode 2, Japanese Code (JSCE) and Canadian Code (CSA) as well as the test results.

A Probabilistic Structural Design Method of Composite Propulsion System (복합재 추진기관의 확률적 구조 설계 기법)

  • Hwang, Tae-Kyung;Kim, Hyung-Kun;Kim, Seong-Eun
    • Journal of the Korean Society of Propulsion Engineers
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    • v.17 no.5
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    • pp.80-85
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    • 2013
  • This paper describes a probabilistic structural design method of composite propulsion system by comparing safety factor based on average value and allowable value with structural reliability. Generally, the required structural safety factor and reliability of composite pressure vessel are 1.5 and 0.999, respectively. In the case of structural design using average strength, the safety factor which satisfies the required structural reliability depends on the variation of fiber strength. However, the structural design using allowable value shows constant safety factor for the variation of fiber strength, because the allowable value of fiber strength is calculated by considering the variation of fiber strength. Through the analysis results, it was known that the fiber strength is the most important design random variable for the structural design of composite pressure vessel and the variation of fiber strength must be minimized to develop the high performance composite propulsion system.

Ultimate Strength Analysis of Slab-Column Joints Subjected to Lateral Loads Using 3-Dimensional Grid Strut-Tie Model Approach (3차원 격자 스트럿-타이 모델 방법을 이용한 횡하중을 받는 슬래브-기둥 접합부의 극한강도 평가)

  • Son, Woo-Hyun;Yun, Young-Mook
    • Proceedings of the Korea Concrete Institute Conference
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    • 2008.11a
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    • pp.265-268
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    • 2008
  • Slab-column joints have been used in the constructions of many structures and buildings. However, as the prediction of the failure behavior and ultimate strength of the joints subjected to lateral loadings is very difficult, the current building and structural design codes do not explain the failure behavior of the joints clearly. In this study, the applicability of the 3-dimensional grid strut-tie model approach, suggested for analysis and design of 3-dimensional structural concrete with disturbed regions, to the ultimate analysis and design of the joints is examined by evaluating the failure strengths of 43 slab-column joints tested to failure. The validity of the 3-dimensional grid strut-tie model approach is also verified by comparing the strength evaluation results with those by ACI 318-05 and FIB 1999.

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Methodology of Strength Analysis of Socket for AL Handrail in Offshore Platform (해양플랫폼 알루미늄 핸드레일 적용을 위한 소켓 구조강도 평가법)

  • Kim, Yeon-Ho;Park, Joo-Shin;Seo, Jung-Kwan
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.28 no.2
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    • pp.354-360
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    • 2022
  • The aluminum handrails used for promoting structural strength and weight reduction of the topside in an offshore platform are designed according to international standards (ISO, NORSOK, and Austria Standard), and consider the most conservative load combinations. Existing aluminum handrails are bolted to a socket when installed on the topside of a platform, and the amount of deflection of the handrail is largely influenced by the socket design. However, the importance of socket design has been overlooked, and furthermore, separate evaluation procedures or guidance for socket design are ambiguous. Therefore, a series analysis was performed for estimating the structural strength of aluminum handrails to obtain the governing parameters that minimize their deflection against loads. Experimental verification was performed to validate the structural safety of the new model, and we confirmed that all were satisfied within allowable deflection according to international standards. The developed model could be used in several areas in the future as it is lighter and more productive compared to existing models from overseas makers.

기술정보

  • 한국레미콘공업협회
    • 레미콘
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    • no.3 s.27
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    • pp.112-119
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    • 1991
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