• Proceedings of the Korea Concrete Institute Conference
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• 2009.05a
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• pp.389-390
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• 2009

Recently, building structure damage and number of lives lost by bomb terror is increasing. Therefore, in this study, present basic data for development of impact resistance performance by evaluation on the impact resistance performance of fiber reinforced concrete by high velocity steel projectile test.

• Bulletin of the Society of Naval Architects of Korea
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• v.33 no.2
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• pp.41-48
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• 1996

함정용 탑재장비의 내충격 성능평가 기술분야에 대한 국내의 연구경험이 일천하여 미해군을 비롯한 선진군사강국의 기술구준에 도달하기 위해서는 해결해야 할 과제가 많이 남아있지만, 그 동안의 선박진동분야에서 축적한 구조동력학 분야의 국내기술을 바탕으로 접근해 간다면 그렇게 어려운 문제만은 아니다. 따라서 최근, 이 분야에 대한 국내의 활발한 연구활동을 시발점으로 하여 보다 심도있고 지속적인 연구를 수행한다면 한국해군 함정 및 탑재장비의 내충격 설계기술 자립을 머지 않아 이를 수 있으리라 생각한다. 이를 위해서 이 분야에 대한 국내연구진의 더 많은 노력과 한국해군의 적극적인 지원을 기대한다.

• Proceedings of the Korean Society of Disaster Information Conference
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• 2015.11a
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• pp.170-171
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• 2015

본 논문에서는 내충격 방폭 성능 강화를 위해 개발된 유기계 단섬유 HPFRCC의 휨인성을 평가하였다. 유기계 단섬유 보강재는 아라미드섬유를 사용하였으며, 아라미드섬유 원사를 섬유가공 방법 중에 하나인 ATY(Air texturd yarn)공법을 통해 단섬유 형태로 제조하였다. 아라미드섬유 보강재를 혼입한 HPFRCC의 휨인성 시험을 통해 아라미드섬유의 내충격 방폭 성능 강화용 섬유보강재로의 성능을 평가하였다.

• Journal of KSNVE
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• v.8 no.1
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• pp.21-28
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• 1998

본 고에서는 미해군을 비롯한 유럽의 선진 군사 강국들이 현재 사용하고 있는 함정용 탑재 장비의 내충격 성능 평가 방법을 살펴보고, 동 기술 개발 분야에 대한 국내의 현황및 향후 기술개발에 대한 국내의 현황및 향후 기술개발 방향에 대해 개괄하고자 한다.

• Journal of the Korea Concrete Institute
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• v.25 no.1
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• pp.107-114
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• 2013

In this study we experimentally evaluated an impact resistant performance of fiber reinforced concrete in the moment of explosion by high-velocity projectile with emulsion explosive. To assess the impact resistance, we conducted the impact test of high-velocity projectile which reaches an impact speed of 350 m/s and the experiment of contact exploding emulsion explosive. As a result, bending and tensile performance depending on type of PVA, PE fiber (polyvinyl alcohol fiber, polyethylene fiber) and steel fiber affects destruction of rear side in the form of spalling. Destroying the backside of the concrete compressive strength compared to suppress the bending and tensile performance is affected. In addition, the experiment shows that the destruction patterns of concrete specimen producted by high velocity impact and contact explosion are significantly similar. Therefore, it is possible to predict the destruction patterns of specimens in the situation of contact explosion by high-velocity projectile.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2000.06a
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• pp.468-471
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• 2000

HDD가 비동작중 외부충격을 받았을 경우에 대해 수치해석을 이용하여 HSA(head stack ass'y)의 거동과 헤드가 디스크 면에서 멀어지는 Lift-off level을 고찰하고, actuator의 arm blade(primary system)의 끝단에 보조의 구조물(auxiliary system)을 붙여 반사인파의 가속도입력에 의해 발생되는 HSA의 진폭을 감소시키고 내충격성능을 향상시키고자 한다. 보조 구조물의 형태와 재료는 arm blade의 공진과 연계한 공진주파수의 최적화과정에 의해 결정된다. 실제 제품의 취급에서 가장 쉽게 발생할 수 있는 0.5ms의 duration time으로부터 제품의 성능평가 요건인 2ms의 duration time까지의 반사인파의 입력에 대한 응답을 고찰한 결과 보조의 구조물을 가졌을 경우 주 시스템보다 훨씬 높은 충격에서 헤드의 lift-off이 발생되어 전체 시스템의 내충격성능을 향상시킴을 알 수 있다.

• Composites Research
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• v.32 no.5
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• pp.290-295
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• 2019

In the present study, composite insulation mat was reinforced over polyurethane foam (PUF) to improve the thermal performance and impact resistance of the PUF applied to the liquefied natural gas carrier insulation system. The composite insulation mat used Kevlar, aerogel, and cryogel composite mat that can be applied in a cryogenic environment. The thermal conductivity was measured at $20^{\circ}C$ to investigate the thermal performance, and the drop impact test was carried out under impact energy of 30 J at $20^{\circ}C$, $-163^{\circ}C$ to investigate the impact resistance. The measured thermal performance was compared with neat PUF through effective thermal conductivity theoretical value. The shock resistance was evaluated of contact force, contact time, and absorb energy. In experimental results, cryogel composite mat was the best performance in terms of thermal performance, and aerogel composite mat was the best performance in terms of impact resistance.

• Journal of the Korea Institute of Building Construction
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• v.23 no.3
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• pp.261-272
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• 2023

This research concentrates on the potential explosion hazards that could arise from unforeseen accidents in the rapidly proliferating hydrogen refueling stations and Energy Storage System(ESS) facilities. It underscores the pivotal role of structural protection technology in alleviating such risks. The research contributes primary data for the formulation of structure protection design by assessing the impact resistance across various reinforcement techniques used in cement composites. The experimental results elucidate that reinforced concrete, serving as the quintessential structural material, exhibits a 20% advancement in impact resistance in comparison to its non-reinforced counterpart. In situations typified by rapid loads, such as those seen with high-velocity impacts, the reinforcement of the matrix with fibers is demonstrably more beneficial than local reinforcement. These insights accentuate the importance of judiciously choosing the reinforcement method to augment impact resistance in structural design.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.41 no.10
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• pp.1005-1009
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• 2017

In this study, the shock resistance of a gas turbine package subjected to a shock load caused by non-contact underwater explosion was investigated using numerical analysis. To perform shock analysis, the time-history shock load was calculated according to BV-043 (German Navy Regulation). The direct transient response analysis in the time domain for the simplified Whole Engine Model (WEM) was performed using the calculated shock load. In addition, the structural integrity of a detailed model was evaluated by considering the shock load transferred to each component. As a result, it was confirmed that the safety factor was at least 1.0 as compared with the reference stress. Finally, the structural and functional integrity of the Engine Management System (EMS) of the gas turbine package was verified through an actual shock test.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.3
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• pp.724-729
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• 2017

The crashworthiness of the fuel tank of a rotorcraft is verified through the crash impact test. The crash impact test has a high risk of failure due to the application of an excessive load, which can seriously affect the overall development schedule of the aircraft. Therefore, a lot of effort has been made to minimize the possibility of failure in the actual test by carrying out a numerical analysis of the crash impact test of the fuel tank in the initial design stage. Recently, an external auxiliary fuel tank was added to increase the cruising distance. In this study, the numerical analysis results of the crash impact test based on several different shapes of the external auxiliary fuel tank are presented, in order to evaluate its crashworthiness. For the numerical analysis, smoothed particle hydrodynamics (SPH), which is one of the fluid-structure coupled analysis methods, is applied and the test conditions prescribed by US military standards are reflected in the analysis conditions. In addition, the material property data previously obtained by the specimen test of the actual fuel tank is applied to the numerical analysis. As a result, the equivalent stress of the fuel tank material itself and the metal fitting is provided and the possibility of acquiring data for designing the crash-worthiness of the external auxiliary fuel tank is evaluated by examining the behavior and working load of the internal mounted components.