• Title/Summary/Keyword: Anti-ram barriers

Search Result 3, Processing Time 0.02 seconds

Performance Evaluation and Proposal on Standard Establishment of the Bollard Through Impact Analysis (충돌해석을 통한 볼라드의 성능평가 및 설치기준 제안)

  • Cha, Eun-Ho;Jeon, Doo-Jin;Han, Sang-Eul
    • Journal of Korean Association for Spatial Structures
    • /
    • v.16 no.4
    • /
    • pp.59-66
    • /
    • 2016
  • Recently damage of structures and loss of life by terrorism are internationally increasing. Among these terror that have a possibility to can happen in korea and that can caused lot of human life loss is the vehicle terror. To prevent the vehicle terror, the anti-ram barriers are needed. But domestic standard about anti-ram barriers are not clear. So, in this study, we will utilize and analyze the vehicle impact to evaluate the efficiency of the domestic bollard and suggest the installation standard of those. In Korea, granite, elastic, steel and stainless bollard are used. The performance of those bollard is not available. Elastic bollard couldn't stop the vehicle, and the others just could stop the vehicle only at the speed under 10kph. Therefore, set the variable to reinforce, and evaluate the defence efficiency of bollard. As a result, granite and elastic bollard was not suitable for the anti-ram barriers. Performance of steel bollard increased as thickness grew. So steel bollard should must be thicker than 10T. And the concrete compressive strength effected insignificantly on the defence efficiency, so more than 24MPa compressive concrete be used. Performance of stainless bollard increased as thickness grew. So stainless bollard should must be thicker than 13T.

Vehicle Collision Simulation for Roadblocks in Nuclear Power Plants Using LS-DYNA (LS-DYNA를 이용한 원자력발전소의 로드블록에 대한 차량 충돌 시뮬레이션)

  • SeungGyu Lee;Dongwook Kim;Phill-Seung Lee
    • Journal of the Computational Structural Engineering Institute of Korea
    • /
    • v.36 no.2
    • /
    • pp.113-120
    • /
    • 2023
  • This paper introduces a simulation method for the collision between roadblocks and vehicles using LS-DYNA. The need to evaluate the performance of anti-ram barriers to prepare for vehicle impact has increased since vehicle impact threats have been included as a design criterion for nuclear power plants. Anti-ram barriers are typically certified for their performance through collision experiments. However, because Koreas has no performance testing facilities for anti-ram barriers, their performance can only be verified through simulations. LS-DYNA is a specialized program for collision simulation. Various organizations, including NCAC, distributes numerical models that have been validated for their accuracy with collision tests. In this study, we constructed a finite element model of the most critical vehicle barrier module and simulated collision between roadblocks and vehicles. The calculated results were verified by applying the validation criteria for vehicle safety facility collision simulations of NCHRP 179.

Radiation-Crosslinked Carboxymethyl Cellulose/Porcine Cartilage Acellular Matrix Hydrogel Films to Prevent Peritoneal Adhesions with physical properties and anti-adhesivity (방사선 가교된 유착방지용 Carboxymethyl Cellulose/Porcine Cartilage Acellular Matrix 수화젤 필름의 물리적 특성 및 부착 방지 평가)

  • Jeong, Sung In;Park, Jong-Seok;Gwon, Hui-Jeong;An, Sung-Jun;Song, Bo Ram;Kim, Young Jick;Min, Byoung Hyun;Kim, Moon Suk;Lim, Youn-Mook
    • Korean Chemical Engineering Research
    • /
    • v.55 no.1
    • /
    • pp.34-39
    • /
    • 2017
  • In this study, intermolecular crosslinked carboxymethyl cellulose sodium salt (CMC) and porcine Cartilage Acellular Matrix (PCAM) blended hydrogel films for anti-adhesive barriers were prepared by gamma-ray radiation. The effects of the CMC/PCAM concentration and blending ratio on the morphology, gel fraction, gel strength, and degree of swelling were determined. The results indicated that crosslinked CMC/PCAM films show significantly lower the gel-fraction than CMC films. The degree of attachment and proliferation of human vascular endothelial cells on CMC/PCAM films was lower than the CMC films. We show the capacity of the CMC and PCAM to be hydrogel films, and the ability to reduce cell adhesion and proliferation on these films by modification with cell anti-adhesion molecules of PCAM. In conclusion, this study suggests that radiation cross-linked CMC/PCAM hydrogel films endowed with anti-adhesion ligands may allow for improved regulation of cell anti-adhesion behavior for prevent peritoneal adhesions.