• Title/Summary/Keyword: Impact protection

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Evaluation of Fracture Behaviours of Cementitious Composites by High-velocity Projectile Impact (고속 비상체 충격에 의한 시멘트 복합체의 파괴거동 평가)

  • Min, Ji-Young;Cho, Hyun-Woo;Lee, Jang-Hwa;Kim, Sung-Wook;Moon, Jae-Heum
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.19 no.6
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    • pp.55-62
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    • 2015
  • An importance of infrastructures' protection against crash or blast loading has been an emerging issue as structures are becoming much bigger and population densities in downtown are growing up. However, there exists no such a standard to evaluate the protection performance of construction material itself. Prior to building standards for protection assessment techniques, this study performed gas-gun propelled projectile impact tests with series of contact-type monitoring systems to investigate the applicability of each sensing type. Through the impact tests, failure modes and protection performances of both normal concrete and UHPC (Ultra High Performance Concrete) reinforced by steel fibers were also evaluated. The results showed that LVDT could be applicable for the impact test among contact-type sensors and UHPC with fibers had a remarkable potential to improve protection against impact loading.

Development Process of Side Impact Beam for Automotive Light-Weighting Door using Sheet Type (자동차 도어 경량화를 위한 판재형 사이드 임팩트 빔 개발 프로세스)

  • Lee, I.C.;Lee, T.K.;Jang, D.H.
    • Transactions of Materials Processing
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    • v.24 no.2
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    • pp.130-137
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    • 2015
  • This paper presents the development process of automotive side door impact beam for passenger cars. Weight reduction while maintaining functional requirements is one of the major goals in the automotive industry. In this study, thin-walled side door beam using quenchable boron steel was designed to reduce the weight of conventional side door tubular one. In order to estimate design for the proposed side door beams, the static side impact protection tests(FMVSS 214) were conducted using the finite element method. Based on the simulation results, geometry modification of the side door beam has been performed via creating new reinforcing ribs. Furthermore, the manufactured frontal impact beam was mounted on the real side door of a passenger car, and then static impact protection test carried out. It is concluded that the presented test results can provide significant contribution to the stiffness of side door impact beams and light-weighting door research.

Impact response of ultra-high performance fiber-reinforced concrete filled square double-skin steel tubular columns

  • Li, Jie;Wang, Weiqiang;Wu, Chengqing;Liu, Zhongxian;Wu, Pengtao
    • Steel and Composite Structures
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    • v.42 no.3
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    • pp.325-351
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    • 2022
  • This paper studies the lateral impact behavior of ultra-high performance fiber-reinforced concrete (UHPFRC) filled double-skin steel tubular (UHPFRCFDST) columns. The impact force, midspan deflection, and strain histories were recorded. Based on the test results, the influences of drop height, axial load, concrete type, and steel tube wall thickness on the impact resistance of UHPFRCFDST members were analyzed. LS-DYNA software was used to establish a finite element (FE) model of UHPFRC filled steel tubular members. The failure modes and histories of impact force and midspan deflection of specimens were obtained. The simulation results were compared to the test results, which demonstrated the accuracy of the finite element analysis (FEA) model. Finally, the effects of the steel tube thickness, impact energy, type of concrete and impact indenter shape, and void ratio on the lateral impact performances of the UHPFRCFDST columns were analyzed.

Evaluation of Occupant Protection of Passenger Vehicles at IIHS Side Impact (소형 승용차량의 측면충돌 시 탑승자 보호성능 평가)

  • Kim, Guanhee;Lim, Jonghun;Lim, Jangho;Park, Insong;Cho, Chongdu
    • Transactions of the Korean Society of Automotive Engineers
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    • v.22 no.1
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    • pp.46-51
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    • 2014
  • 2,097 deaths out of 5,229 by traffic accident occurred by vehicle to vehicle crash and 855 deaths out of 2,097 occurred at side crash in 2011. Korean government adopted New Car Assessment Program to reduce the wounded and deaths at traffic accident in 1999 and side impact test has been added in 2003. 43 out of 53 vehicles tested in NCAP side impact rated 4 and 5 stars means the highest occupant protection. In this study three small class vehicles have been tested according to Insurance Institute for Highway Safety's side crashworthiness test protocol. IIHS test protocol uses 1,500kg moving barrier rather than NCAP's 950kg and the occupant protection rated Good, Acceptable, Marginal and Poor based on injury measure, structural integrity and head protection.

An Analysis Measure for Cybersecurity linked Threat against Diverse Protection Systems (다양성보호계통 사이버보안 연계 위협 분석 방안)

  • Jung, Sungmin;Kim, Taekyung
    • Journal of Korea Society of Digital Industry and Information Management
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    • v.17 no.1
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    • pp.35-44
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    • 2021
  • With the development of information technology, the cybersecurity threat continues as digital-related technologies are applied to the instrumentation and control system of nuclear power plants. The malfunction of the instrumentation and control system can cause economic damage due to shutdown, and furthermore, it can lead to national disasters such as radioactive emissions, so countering cybersecurity threats is an important issue. In general, the study of cybersecurity in instrumentation and control systems is concentrated on safety systems, and diverse protection systems perform protection and reactor shutdown functions, leading to reactor shutdown or, in the worst case, non-stop situations. To accurately analyze cyber threats in the diverse protection system, its linked facilities should be analyzed together. Risk analysis should be conducted by analyzing the potential impact of inter-facility cyberattacks on related facilities and the impact of cybersecurity on each configuration module of the diverse protection system. In this paper, we analyze the linkage of the diverse protection system and discuss the cybersecurity linkage threat by analyzing the availability of equipment, the cyber threat impact of the linked equipment, and the configuration module's cybersecurity vulnerability.

Development and Evaluation of Fall Impact Protective Clothing for the Elderly Women (여성 노인을 위한 낙상충격 보호팬츠 개발 및 평가)

  • Park, Jung Hyun;Lee, Jin Suk;Lee, Jeong Ran
    • Fashion & Textile Research Journal
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    • v.20 no.5
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    • pp.569-582
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    • 2018
  • The purpose of this study is to verify the impact protection performance and to evaluate the activity, design, fit, and pad characteristics of the fall impact protection clothing for elderly women. The protective clothing was designed as pants type and underwear type, and an impact protection pad in the form of a tightly connected regular hexagon piece was inserted in the hip and hip joints. The pad was made of two kinds of foam single pad and foam and gel combination pad so that they could be inserted into pants type and underwear type, respectively. The results of the shock absorption performance of the fall impact protective clothing showed that when the impact force of 4601N was applied to the pants type protective clothing, the impact force was reduced by 29% in the foam pad type and 26% in the gel and foam pad type. When the force of 5113N was applied to the underwear type, it decreased by 40% in the foam pad type and by 34% in the gel and foam pad type. As a result of wearing evaluation of subject group, it was found that fit and activity of underwear type was better than that of pants type. Foam pad type was evaluated to be lighter than gel and foam pad type in both the subject and the expert group and the gel and foam pad was evaluated to be more flexible in the expert group.

Environment Assessing for Airborne Radioactive Particulate Release-introduction of Methods in IAEA Safety Report Series No.19

  • Meng, Dan;Yang, Liu;Shen, Fu;Yang, Yi;Ma, Yinghao;Ma, Tao;Zhang, Zhilong;Fu, Cuiming
    • Journal of Radiation Protection and Research
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    • v.41 no.4
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    • pp.409-417
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    • 2016
  • Background: Airborne radioactive particulate in many important nuclear facilities (particularly nuclear power plants) will have a strong impact on the relative public dose if they are released into the corresponding environment traversing the stack or vents. The radiation protection researchers have regarded the relative environment assessing and estimation of public doses. And the model of assessing impact of discharges radioactive substance to the environment have been recommended by many international organizations (e.g. IAEA) with the nuclear energy safety and radiation protection. Materials and Methods: This paper introduced the generic models that were suggested by International Atomic Energy Agency (IAEA), for use in assessing the impact of discharges of radioactive substances to the environment (e.g. IAEA Safety Report Series No.19). Results and Discussion: The writers of this paper, based on the recommend methods, assessed the discharge limits in some airborne radioactive substances discharging standards. The reasons that IAEA method are introduced are mainly the following considerations: IAEA is one of international organizations with some authorities in the nuclear energy safety and radiation protection; and, more important, the recommend modes are operational methods rather than the methods having little operations such as that have used by some researchers. Conclusion: It is wish that the introduced methods in this paper can be referenced in draft or revise of the standards related to discharges of radioactive substances to the environment.

A Consideration on the Results of Side Impact and Pole Side Impact Tests in 2011 KNCAP (2011 KNCAP 측면충돌 및 기둥측면충돌 시험결과 고찰)

  • Lee, Dongjun;Choi, Youngtae;Lee, Kwangwon;Lim, Jaemoon
    • Journal of Auto-vehicle Safety Association
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    • v.3 no.2
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    • pp.22-27
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    • 2011
  • The side impact test in the Korean New Car Assessment program (KNCAP) has been conducted since 2003. The side impact test method has been contributed to the improvement of the vehicle side structure and the enhancement of the occupant protection performance for the domestic vehicles. The pole side impact test method introduced in the KNCAP in 2010 to enhance the head protection under the severe side crash environment. The pole side impact test is optional for the additional score to be added to the overall rating score. The test results of side and pole side impact test for five vehicles were introduced and compared.

Introductive Study to the Antarctic Environmental Impact Assessment in Korea (우리나라의 남극 환경영향평가제도 정착을 위한 연구)

  • Choi, Jae-Yong;Choi, Jun-Gyu;Choi, Jun-Young
    • Ocean and Polar Research
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    • v.26 no.2
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    • pp.155-163
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    • 2004
  • The Protocol on Environmental Protection to the Antarctic Treaty was ratified in 1991. With the aim to ensure comprehensive protection of the Antarctic environment, it contains provisions on environmental protection and conservation of the Antarctic area, including provisions for Environmental Impact Assessment. Environmental Impact Assessment is a method used to predict environmental impacts at an early stage in project planning and design, and find ways to mitigate or prevent adverse impacts in order to maintain balance between development activities and environmental conservation. Internationally, the Environmental Impact Assessment (EIA) in the Antarctic is classified into three types - preliminary, Initial, and Comprehensive - based on the environmental impacts of the proposed activities. In case of the Preliminary Environmental Review (PER), proposed activity may proceed in accordance to the national procedures and drafting of an outline. However, Initial (IEE) and Comprehensive Environmental Evaluation (CEE) assess and verify the impacts of the proposed activity, and require methods or alternatives for mitigating or eliminating negative impacts on the environment. Although Korea's Act of 'Activities and Environmental Protection in Antarctica' also includes provisions on EIA for activities in Antarctica, there are obvious contrasts with the EIAs currently being conducted in Korea, in regards to deciding the level of EIA through screening and identifying key issues for assessment through scoping. In order to implement the proper EIA, more improved methods for drafting and reviewing the EIA to Antarctica in Korea are necessary.