• Title/Summary/Keyword: 방호구조

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Performance Analysis of Steel-FRP Composite Safety Barrier by Vehicle Crash Simulation (충돌 시뮬레이션을 활용한 강재-FRP 합성 방호울타리의 성능평가)

  • Lee, Min-Chul;Kwon, Ki-Young;Kim, Seung-Eock
    • Journal of the Korean Society for Advanced Composite Structures
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    • v.2 no.4
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    • pp.11-18
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    • 2011
  • In this study, the performance of a steel-FRP composite bridge safety barrier was evaluated through vehicle crash simulation. Surface veil, DB and Roving fibers were used for FRP. The MAT58 material model provided by LS-DYNA software was used to model FRP material. Spot weld option was used for modeling contact between steel and FRP beam. The structural strength performance, the passenger protection performance, and the vehicle behavior after crash were evaluated corresponding to the vehicle crash manual. As the result, A steel-FRP composite safety barrier was satisfied with the required performance.

An Experimental Study on Development Connection System of Concrete Barrier in Modular Bridges (조립식교량의 콘크리트 방호울타리 연결시스템 개발을 위한 실험적 연구)

  • Jung, Ho Sung;Lee, Sang Seung;Choi, Jin Woong;Kim, Tae Wan;Park, Sun Kyu
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.16 no.2
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    • pp.49-57
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    • 2012
  • Recently, in field of bridge construction, modular technology has been studied to reduce construction period. However, main stream of the study is limited to the pier, girder and deck of bridge, which are huge or main members. Studies on incidental facilities like concrete barrier is out of sight. Thus, in this study, connection system of concrete barrier was developed to apply to modular bridges and static experiment was performed in order to verify structural capability of proposed system. Variables of experiment are composed of bolt direction such as vertical and horizontal. The experimentation due to the designed variables was conducted by comparison with a standard concrete barrier, which is a traditional barrier. As a result, vertical joint way of the bolt showed nearly identical structural performance and healthy to standard specimen's. it can be applied to modular bridges.

Analysis of Ship Collision Behavior of Pile Supported Structure (파일지지 구조물의 선박 충돌거동에 대한 해석)

  • Bae, Yong Gwi;Lee, Seong Lo
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.28 no.3A
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    • pp.323-330
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    • 2008
  • The ship collision analysis of steel pile group as protection system of bridge in navigable waterways was performed to analyze the structural characteristics of protective structure during ship collision. The analysis encompassed finite element modeling of ship and pile, modeling of material non-linearity, hard impact analysis, displacement-based analysis and soft impact analysis for collision scenarios. Through the analysis of hard impact with a rigid wall, impact load for each collision type of ship bow was estimated. In the displacement-based analysis the estimate of energy which protection system can absorb within its maximum horizontal clearance so as to secure bridge pier from vessel contact during collision was performed. Soft impact analysis for various collision scenarios was conducted and the collision behaviors of vessel and pile-supported protection system were reviewed for the design of protection system. The understanding of the energy dissipation mechanism of pile supported structure and colliding vessel would give us the optimized design of protective structure.

Evaluation of the Protection Performance of SB4 Class Concrete Barrier with Anti-Glare Function (SB4 등급 방현기능 콘크리트 방호울타리의 방호성능 평가)

  • Joo, Bongchul;Hong, Kinam;Yun, Junghyun;Lee, Jaeha;Kim, Jungho
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.25 no.1
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    • pp.93-102
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    • 2021
  • This paper describes the process of developing a concrete median barrier of SB4 grade with anti-glare function. The development section has a height and width of 1,270mm and 560mm, respectively. A wire mesh is placed in the center of the cross section to improve the protection performance. Collision analysis predicted that this section satisfies the strength and occupant protection performance, and that no damage to the barrier occurs. In the actual collision test, it was confirmed that this section satisfies the strength and occupant protection performance. However, damage was observed on two concrete barrier when the truck crashed. In order to improve the accuracy of the collision analysis of the concrete barrier in the future, it is considered that a study on the model development and continuous collision analysis method for domestic commercial vehicles should be carried out.

Development of Guardrail End Treatment System using LS-DYNA (LS-DYNA를 이용한 차량방호울타리 단부처리 시설의 개발)

  • IN, Younggun;Shin, Kwanghee;Bae, Kihun
    • Journal of the Society of Disaster Information
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    • v.12 no.3
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    • pp.279-285
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    • 2016
  • Road sides safety barrier system is the last safety during traffic accident. The structural performance of a roadside safety barrier should be kept above expectations. It is possible to protect the passenger's life. End treatment part is installed in the end of the barrier it prevents a phenomenon in which for the vehicle for the guardrail during a vehicle collision it is facility of the absorbing of car crashed impact. By repeated analysis through computer simulation for improving the vehicle crash it will be able to develop crash barriers to respond appropriately to various parameters.

Metal Matrix Composite(MMC) Layered Armour System (금속복합판재 적용 다층 구조 방호성능 평가)

  • Lee, Minhyung;Park, Sang-Won;Jo, Ilguk
    • Journal of the Korea Institute of Military Science and Technology
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    • v.20 no.6
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    • pp.752-757
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    • 2017
  • Analysis has been performed for the penetration of a long-rod into MMC/Ceramic layered armour system with several shot test and a series of simulations. Two types of MMC plate have been fabricated by a liquid pressing method; A356/45%vol.%SiCp with a uniform distribution of SiC particle and Al7075/45%vol.B4Cp with B4C particle. The mechanical properties were measured with the high-speed split Hopkins bar test, hardness test and compression test. The popular Simplified Johnson-Cook model was adopted to represent the material characteristics for FEM simulations. The performance of the MMC applied armour system has been made by comparing with the semi-infinite mild steel target using the depth of penetration(DOP). The results show that placing ceramic front layer provides a certain gain in protection, and that placing another ductile front layer provides a further gain. The application of MMC is found to be attractive.

Study on Cracking Causes and Patterns in Median Barrier and Guardrail Concrete in RC Bridge (콘크리트 교량 방호벽의 균열원인 및 패턴 분석에 대한 연구)

  • Choi, Se-Jin;Choi, Jung-Wook;Kwon, Seung-Jun
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.18 no.5
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    • pp.19-26
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    • 2014
  • Concrete guide rail and median barrier are an attached RC member, however they are vulnerable to cracking due to slip form construction and large surface of member. In this study, causes and pattern of cracking are analyzed through assessment and NDT (Non-Destructive Technique) evaluation for concrete guide rail and median barrier on highway structure. For this work, analysis on drying shrinkage and hydration heat are performed considering installation period, and plastic shrinkage is also analyzed considering their environmental conditions. From the evaluation, plastic settlement around steel location, drying/ plastic shrinkage, and aggregate segregation are inferred to be the main causes of cracking in the structures. The crack causes and patterns are schematized and techniques of crack-control are suggested. Furthermore concrete guide rail/ median barrier in the bridge on the sea are vulnerable to cracking at early age so that special attentions should be paid at the stages of material selection and construction.

Structural Analysis Models to Develop Live Load Distribution Factors of Simply Supported Prestressed Concrete I-Girder Bridge (활하중 분배계수식 개발을 위한 I형 프리스트레스트 콘크리트 거더 교량의 구조해석 모델)

  • Lee, Hwan-Woo;Kim, Kwang-Yang
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.21 no.1
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    • pp.91-101
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    • 2008
  • Structural analysis models to develop live load distribution factors of simply supported prestressed concrete I-girder bridge should have the precision of the analysis results as well as modeling simplicity. This is due to the numerous frequency of structural analysis needed while developing live load distribution factors. In this study, an appropriate structural analysis model is selected by comparing previous researchs studies and models used in practical design. Also, the influence by the flexural stiffness of barrier and diaphragm on the live load distribution had been analyzed through comparing the numerical analysis and experimental tests. As a result, the model that the eccentric girder and the barrier and diaphragm are connected to the deck plate was appropriate in satisfying both accuracy and simplicity for structural analysis of simply supported prestressed concrete I-girder bridge. However, the barrier was analyzed to have insignificant influence on the live load distribution in spite of its variation of stiffness. The eccentric diaphragm showed little influence at 25% or higher of flexural stiffness. From the results, a model that the girder is rigidly connected to the deck plate in consideration of the eccentricity, the barrier is ignored and the whole section of diaphragm is supposed to be valid without eccentricity is decided as the most appropriate structural model to develop the live load distribution factors of simply supported prestressed concrete I-girder bridge in this study.

Structural Analysis of Impact·Blast Resistant Composite Panel using ACP and AUTODYN (ACP와 AUTODYN을 이용한 방호·방폭 보강 복합패널 구조해석)

  • Kim, Woonhak;Kang, Seokwon
    • Journal of the Society of Disaster Information
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    • v.12 no.4
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    • pp.432-439
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    • 2016
  • To make a model of a Impact/Blast resistant composite material and perform the analysis, material properties of the composite material are required. In order to obtain such a property value, it is necessary to input the result obtained by performing a lot of material tests by the calculation formula of the situation, and there is a lot of difficulty in the case of a special purpose material which is not a general material. In this study, modeling and structural analysis of composite fiber panels for protection and explosion - proofing were performed in ACP(ANSYS Composite PrePost) and AUTODYN by applying the application properties of composites provided in Ansys Workbench environment.