• Title/Summary/Keyword: Structural Safety

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Optimum Safety Indices Based On Expected Total Cost Minimization (총기대비용 최소화원칙에 의한 최적신뢰성지수)

  • 이증빈;신형우;장석모
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 1993.10a
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    • pp.216-223
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    • 1993
  • The safety factors of current standard code are considered to be not appropriate compared to design and construction practices, even this safety factors are not determined from probabilistic study but merely from experiences and practices. This study pripose the optimum safety indices based on expected total cost minimization using only three parameters, which are the level of the failure cost to the initial cost by improvement in safety, and the order of the initial cost function.

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Investigation of Structural Safety of Monobloc Tubular Drive Shaft Subjected to Torque (비틀림 모멘트가 부가되는 일체형 중공 드라이브 샤프트의 구조 안정성 분석)

  • Guk, Dae-Sun;Ahn, Dong-Gyu;Lee, Ho-Jin;Jung, Jong-Hoon
    • Journal of the Korean Society for Precision Engineering
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    • v.32 no.12
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    • pp.1073-1080
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    • 2015
  • A drive shaft is used to transmit torque and rotation through the connection of components of a drive train. Recently, a monobloc drive shaft without welding regions is developed to improve the safety of the drive shaft. The drive shaft bears the shear stress induced by torque. The objective of this paper is to investigate into the structural safety of a monobloc tubular drive shaft subjected to torque. Elasto-plastic finite element (FE) analysis is performed to estimate the deformation behavior of the drive shaft and stress-strain distribution in the drive shaft. Several techniques are used to create finite element (FE) model of the monobloc tubular drive shaft subjected to torque. Through the comparison of the results of FE analyses with those of experiments from the viewpoint of rotational angle, appropriate correction coefficients for different load conditions are estimated. The safety of the tubular drive shaft is examined using the results of FE analyses for different load conditions. Finally, it is noted that the designed tubular drive shaft has a sufficient structural safety.

Probabilistic Structural Safety Assessment Considering the Initial Shape and Non-linearity of Steel Cable-Stayed Bridges (강사장교의 초기형상과 비선형성을 고려한 확률론적 구조안전성 평가)

  • Bang, Myung-Seok;Han, Sung-Ho;Lee, Woo-Sang;Lee, Chin-Ok
    • Journal of the Korean Society of Safety
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    • v.25 no.3
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    • pp.91-99
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    • 2010
  • In this study, the advanced numerical algorithm is developed which can performed the static and dynamic stochastic finite element analysis by considering the effect of uncertainties included in the member stiffness of steel cable-stayed bridges and seismic load. After conducting the linear and nonlinear initial shape analysis, the advanced numerical algorithm is the assessment tool which can performed structural the response analysis considering the static linearity and non-linearity of before or after induced intial tensile force, and examined the reliability assessment more efficiently. The verification of the developed numerical algorithm is evaluated by analyzing the regression analysis and coefficient of correlation using the direct monte carlo simulation. Also, the dynamic response characteristic and coefficient of variation of the steel cable-stayed bridge is calculated by considering the uncertainty of random variables using the developed numerical algorithm. In addition, the quantitative structural safety of the steel cable-stayed bridges is evaluated by conducting the reliability assessment based upon the dynamic stochastic finite element analysis result.

Performance Evaluation of Seismic Stopper using Structural Analysis and AC156 Test Method

  • Ryu, Hyun-su
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.26 no.3
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    • pp.277-285
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    • 2020
  • Recently, studies have been actively conducted on seismic design and improvement of the seismic performance of bridges, buildings, factories, and plants. In particular, heavy items that are being manufactured or waiting to be shipped from factories (such as generators, engines, and boilers) must be equipped with seismic stoppers to prevent them from moving or falling during an earthquake. Seismic stoppers should be suitably determined by the size and weight of these heavy items; however, they have no general design standard. In this study, structural analyses and seismic tests were conducted to evaluate the performance of newly designed seismic stoppers. Structural analysis was performed on three stopper models to estimate the external load at which the yield stress of the material was not exceeded. Based on the analysis results, a seismic test of the stopper was carried out in accordance with the AC156 test method. Finally, product specifications for all three seismic stopper models were determined and their static/dynamic load performance was evaluated.

Local Zooming Analysis of LNGC CCS under Sloshing Impact Loading (LNG선 단열시스템의 슬로싱 충격하중에서의 국부확대해석)

  • Lee, Sang-Gab;Hong, Anh;Cho, Heon-Il;Kim, Jin-Kyung;Ahn, Ji-Woong
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 2011.04a
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    • pp.544-551
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    • 2011
  • As the cargo tank size and configuration of Liquefied Natural Gas carriers(LNGC) grows in response to the global increase in demands for LNG and the necessities of its economical transportation, impact loading from sloshing may become one of the most important factors in the structural safety of LNG Cargo Containment Systems(CCS). The objective of this study is to demonstrate the procedure of the structural safety assessment of MARK III membrane type CCS under sloshing impact loading using local zooming analysis technique of LS-DYNA code.

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Structural Safety Assessment of Dropped Object in Laydown Area of FSU (부유식 원유저장 해양구조물 하역구역 내의 낙하물 충격 구조 안전성 평가)

  • Lee, Sang-Gab;Lee, Ji-Hoon;Noh, Jae-Hyun;Lee, In-Ho;Kim, Tae-Dong;Kim, Joo-Hwan
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 2010.04a
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    • pp.122-125
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    • 2010
  • 본 논문에서는 부유식 원유저장 해양구조물(FSU; Floating Storage Unit)의 상부 하역구역(Laydown Area) 내에 낙하물(Dropped Object)이 떨어질 경우의 충격 구조 안전성 평가(Structural Safety Assessment)를 수행하여 표준해석 절차서를 정립하고자 한다. 이를 위해서는 내충격 구조해석을 통한 평가 기법을 개발하고 그 기법의 적용성을 검토하여 표준해석 절차서를 정립하는 것이 필요하다. 현재는 충격 구조해석 시나리오를 작성하고 내충격 구조해석을 수행하여 설계기준(design criterion)에 적용하고 있는 중간단계로써 그 결과들을 소개하고자 한다.

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Structural Behavior of Sawdust-Mixing Concrete (폐톱밥 혼입 콘크리트의 구조거동에 관한 실험적 연구)

  • Hong, Seung-Ryul;Son, Ki-Sang
    • Journal of the Korean Society of Safety
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    • v.20 no.3 s.71
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    • pp.126-133
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    • 2005
  • Behavior of saw-dust concrete has not studied because many people have thought that saw-dust concrete cannot be applicable for structural member, up to now. This study is to findout how much the concrete can be structurally applicated. 5mm grid sieve was used to select satisfactory sawdust for better concrete quality. Test molds size of ${\phi}10{\times}20cm$ long were made of normal without sawdust, 0.05%, 0.1%, 0.2%, 0.4%, 0.6%, 0.8%, 1.0%, 1.2%, 1.4%, 1.6%, 1.8% 2.0%, for making concrete strengh of 180kg, 210kg, 240kg, 270kg which they are normally used in practice presently. A various strengths tests such as compressive splitting tensile, flexible strength behavior of structural member named beam using size of $20{\times}30{\times}120cm$ have been done for the structural aspects. Tensile strength shows that it can be more affected than higher strength of it.

Application of Structure Maintenance and Management Using GIS (GIS를 이용한 구조물 유지관리 적용)

  • Lee, Jong-Chool;Kim, Hee-Gyoo;Roh, Tae-Ho;Nam, Shin
    • Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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    • 2003.10a
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    • pp.291-295
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    • 2003
  • For rapid development of science and economic growth, modern constructs are higher and large in order to use confined areas efficiently. Also, it is very important to manage efficient data for safety and maintenance of those constructs. The estimation for structural safety can be evaluated by structural durability and safety using data which surveys various elements. So, it should be based on synthetic and efficient data which includes various elements with related safety of those structures. Then, it will be managed properly and economically. Accordingly, in this study, we would approach efficient maintenance management using the GIS with data from structural-safety diagnosis.

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Dynamic Analysis and Structural Safety Evaluation of the Cabinet of a Reactor Safety System (원자로 보호계통 캐비닛의 동해석과 구조 안전성 평가)

  • Lee, Boo-Youn;Cho, Chung-Rae;Kim, Won-Jin;Jeong, Dong-Gwan;Shon, Jae-Youl
    • Journal of the Korean Society for Precision Engineering
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    • v.22 no.12 s.177
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    • pp.131-140
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    • 2005
  • Responses of the cabinet of the reactor safety system under seismic leadings are analyzed, its dynamic characteristics and structural reliability being evaluated. Analyzed natural frequencies are compared with those measured from a resonance test. Structural safety of the cabinet is evaluated in consideration of the required response spectrums of the operation-base and safe-shutdown earthquakes. Transient responses of the cabinet are analyzed with input ground acceleration measured during the seismic test, accelerations being extracted at the locations of the main internal parts. The transient responses are compared with those from the seismic test, favorable results being shown.