• Title/Summary/Keyword: Impact protection performance

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Impact conditions of motorcyclists on road protection systems by numerical simulation

  • Peng, Li;Brizard, Denis;Massenzio, Michel
    • Structural Engineering and Mechanics
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    • v.82 no.2
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    • pp.233-244
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    • 2022
  • Following a loss of control, the impact against a road barrier in a turn predominates among the most severe motorcyclist accidents. These road restraint devices can be equipped with a motorcycle screen, the function of which is to restrain the rider and minimize the consequences of the impact in terms of the severity of injuries. The performance of these screens is evaluated by the European normative procedure EN1317-8, which specifies the test conditions, based on one or two configurations. In practice, however, these impact conditions are very diverse, difficult to extrapolate from accident analysis and therefore poorly investigated. This study is interested in improving knowledge of these impact conditions in terms of impact speed, impact angle and particularly position of the rider. A finite element model has been developed to simulate the dynamic behavior of the rider from loss of control to impact on the screen. Statistical analysis of the results shows a high variability of the impact conditions, in particular with regard to the direction of turn (to the right or to the left). Some improvements are suggested in order to overcome the limitations inherent in standard procedures.

A Study on the local Environmental Impact Assessment in Germany (독일 지방자치단체환경영향평가제도 연구)

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    • Journal of Environmental Science International
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    • v.11 no.6
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    • pp.463-470
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    • 2002
  • Environmental protection and precaution are the most frequently considered issues in the recent research fields for our present and future surroundings. However, it seems that these environmental issues were less reflected in local-level development plans, and caused several cases of environmental pollution, therefore it became a major concern of local governments and the communities. The role of a 'Local EIA(Environment Impact Assessment)' can be a core issue for the positive preferences of the local-level development plans. Cases of Local EIA in Germany which have been implied successfully are reviewed to generate a local EIA movement and to produce a guideline for Korean local governments. The local EIA in Germany was broadly commenced in the middle of 1980s, and a decade later it was carried out for over 200 of local governments. To produce a better suggestion for Korean local EIA, comparison and analysis of detail data of the German local EIA was carried out, and tested for fourteen cities in Korea based on five categories: i) assessment subject, ii) assessment procedure, iii) main office for assessment, iv) assessment factor and v) assessment standard. Prior suggestions for greater preference of local EIA in Korea are: it is necessary that I) launch of a support system in central government to help the movement of local government; Ⅱ) a knowledge-based expert group in local government which has by all means of exclusive responsibility far any action(new application or performance of local EIA) : 111) establishment of 'environmental protection measure' in local government level for environmental precaution based on individual environmental character and values in their communities.

Impact Resistance Characteristics of HPFRCC Depending on Various Fiber Replacing Ratio (섬유혼입율 변화에 따른 HPFRCC의 내충격 특성)

  • Park, Yong-Jun;Kim, Dae-Gun;Mun, Gyeong-Sik;Han, Sang-Hyu;Kim, Gyu-Yong;Han, Cheon-Goo
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2015.05a
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    • pp.75-76
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    • 2015
  • This study has examined the impact resistance and blast resistance characteristics of HPFRCC as a research on impact resistance and blast resistance characteristics using high volume mortar and high velocity projectile for evaluating the protection performance of actual buildings as small quantity experiment of laboratory conditions is performed although there was an instance of performing research on mortar that has reinforced fiber followed by the rise of problems on the damage of human life and buildings created due to explosion and shock. As a result, the destruction loss area and depth have decreased in case of the surface compared to the rear side. As tensile strength and tenacity have increased with the increased fiber replacing ratio, a tendency of destruction loss area and depth getting decreased was shown as the impact resistance has increased.

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Investigation Into Protection Performance of Projectile Using Flying Plate (판재를 이용한 초고속 위협체의 방호성능에 대한 해석적 연구)

  • Choi, Hyoseong;Shin, Hyunho;Yoo, Yo-Han;Park, Jahng Hyon;Kim, Jong-Bong
    • Journal of the Korean Society for Precision Engineering
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    • v.33 no.12
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    • pp.1039-1045
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    • 2016
  • We investigated the protection capability of a plate against high speed projectiles demonstrating collision and penetration behaviors by finite element analysis. The element erosion method was used for penetration analysis, which showed that the speed of the projectile was slightly reduced by the collision with the protection plate. Protection capability was measured by the projectile's attitude angle change because the damage of our tanks by projectiles was also dependent on the projectile-tank collision angle. When the length of the protection plate was sufficiently long, the projectile was severely deformed and incapacitated. In the case of a small plate, the projectile was deformed only in the collision region. Thus, projection capability was investigated by the change of attitude angle. The effect of collision angle, velocity, and length of the plate on the rotational and vertical velocities of the projectile was investigated.

The Effects of External Search Strategy on Innovation Performance: In the Context of Korean SMEs (외부 정보 탐색 전략이 혁신 성과에 미치는 영향에 대한 연구: 한국 중소기업을 대상으로)

  • Sim, Jeong Eun;Lim, Mi-Hee
    • Korean small business review
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    • v.41 no.2
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    • pp.1-24
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    • 2019
  • This paper seeks to explore the effects of search strategies on innovation performance in the context of small and medium enterprises. The empirical results of 3,398 Korean SMEs demonstrate that there is a substitutive relationship between search depth and search width, and this substitutive relationship is weakened when a firm possesses collaboration experience. Furthermore, although these two types of search enhance innovation performance, the impact of search depth is greater than that of search width. The positive effect of search width on innovation performance is weakened when the firm adopts formal information protection mechanisms.

A Study on Test Method for Performance Evaluation of Rockfall Protection Fence (Post) (낙석방지울타리(지주) 성능평가를 위한 시험방법 연구)

  • Jin, Hyunwoo;Hwang, Youngcheol
    • Journal of the Korean GEO-environmental Society
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    • v.23 no.2
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    • pp.5-12
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    • 2022
  • In this study, a field test was conducted to present a test method for performance evaluation of a rock fall prevention fence, centering on the vertical drop test among the existing test methods of the rock fall prevention fence. A test to determine the support capacity of a rockfall prevention fence in Korea is usually conducted using a combination of wire mesh, poles, and wire rope, and the location of the impact of falling rocks has been conducted centered on the center of the wire mesh. However, in the case of domestic papers and test data, there is no data on direct hit of post. Therefore, the amount of displacement and weak section were analyzed when the impact on 100kJ class rock energy was hit on the post, centering on the Rockfall Protection fence (highway type No. 2).

Basic Study on Fiber Composite Panel Production for Impact·Blast Resistant (방호·방폭 보강용 복합섬유 패널 제작을 위한 기초연구)

  • Kim, Woonhak;Kang, Seokwon;Yun, Seunggyu
    • Journal of the Society of Disaster Information
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    • v.11 no.2
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    • pp.235-243
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    • 2015
  • The methods to improve the protection and explosion-proof performance of concrete structures include the backside reinforcement or concrete material property improvement and the addition of structural members or supports to increase the resistance performance, but they are inefficient in terms of economics and structural characteristics. This study is about the basic study on the fiber composite panel cover, and the nano-composite material and adhesive as the filler, to maximize the specific performance of each layer and the protection and explosion-proof performance as the composite panel component by improving the tensile strength, light weight, adhesion and fire-proof performances. The fiber composite panel cover (aramid-polyester ratios of 6:4 and 6.5:3.5) had a 2,348 MPa maximum tensile strength and a 1.8% maximum elongation. The filler that contained the nano-composite material and adhesive had a 4 MPa maximum tensile shear adhesive strength. In addition, the nano-composite filler was 30% lighter than the normal portland cement

Performance Evaluation of Composite Safety Barrier for Bridge by Vehicle Impact Simulation (차량 충격 시뮬레이션을 통한 복합소재 교량용 방호울타리의 성능 분석)

  • Kim, Seung-Eock;Jeon, Shin-Youl;Hong, Kab-Eui;Lee, Min-Chul
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.24 no.5
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    • pp.499-506
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    • 2011
  • In this study, the performance of composite safety barriers was evaluated through computer simulation. A composite safety barrier of SB4 grade was modeled. The MAT58 material model provided by LS-DYNA software was used to model composite material. The performance of composite material varies according to fiber, resin type, and fiber direction. Polyurethane resin and glass fiber were used. The performance of three different stacking designs was evaluated by carrying out vehicle impact simulation. The performance evaluation based on the vehicle crash manual includes the structural strength performance, the passenger protection performance, the vehicle behavior after crash, scattering of the guardrail. As the result of the finite element analysis, the barrier composed of the more transverse direction fibers shows the better performance on the impact simulation.

Empirical analysis on Information Management Performance Impact of Information Security activities (정보보호 활동이 정보경영성과에 미치는 영향에 관한 실증분석)

  • Son, Tae Hyun;Park, Jung Sun
    • Journal of the Korea Safety Management & Science
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    • v.17 no.3
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    • pp.205-213
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    • 2015
  • This study aims to verify the structural correlation empirically between information security performance and information management performance. To verify the correlation, three factors such as managerial controlled activity, technical controlled activity, and physical controlled activity are divided for the information security activities variable. the security performance are divided into accident prevention and accident response variables. As a result, security organization activity is a unique factor being positively significant to information security and management performance. And three activities such as human security, security training, development security do not affect at all on both information security and management performance.

Development of Firefighters' Personal Protective Clothing with Nomex Honeycomb Fabric and its Protective and Comfort Evaluation (노멕스 허니콤 구조 직물을 적용한 소방관용 특수방화복 개발 및 이의 보호 쾌적 성능평가)

  • Jung, Jae-Yeon;Ku, Ponjun;Kim, Do Hyung;Kwon, Min-Jae;Kang, Sungwook;Choi, Jeong-Yoon;Lee, Joo-Young
    • Fashion & Textile Research Journal
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    • v.21 no.5
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    • pp.606-617
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    • 2019
  • The present study newly developed a firefighters' protective jacket and pants using a Nomex honeycomb structured layer (HPC) in cases of being exposed to flashover or flameover. This study evaluated the protective and comfort functions of an HPC compared to the current KFI firefighters' protective clothing (FPC). The results are as follows. First, thermal protective performance (TPP) of fabric layers was 2.75 times greater for HPC than FPC at $125kW/m^2$. Second, the predicted second and third degree burn areas were smaller for HPC than FPC when using a flame manikin. Third, thermal insulation using a thermal manikin was 0.2 clo greater for HPC than FPC. Fourth, there were no marked differences in maximal performance, mobility, and microclimate temperature/humidity between FPC and HPC through human wear trials. The thermal insulation of HPC was higher than that of FPC; however, any negative effect of HPC thermal insulation on the comfort functions for firefighters was not found. In conclusion, the newly-developed HPC provided more protection in reducing burn injuries from $125kW/m^2$, while no negative impact on maximal performance, mobility and thermal comfort functions of firefighters, which is appropriate for quick-evasive tactics at the flashover, flameover or back draft fires.