• Journal of the Korean Society for Precision Engineering
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• v.19 no.7
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• pp.7-19
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• 2002

• Journal of the Korean Society of Clothing and Textiles
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• v.25 no.9
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• pp.1661-1668
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• 2001

본고는 지뢰 방호복을 개발, 국산화하기 위해 먼저 방탄소재 구성방법에 관하여 실험한 결과이다. 기존의 여러 겹의 파라-아라미드(Para-aramid)나 단순히 파라-아라미드와 폴리 에틸렌 필름(Polyethlene film)을 조합한 소재구성과는 달리 케블라 파이버(Kevlar fiber)로 만들어진 펠트(felt)를 첨가하여 방탄원리 및 특성을 고려한 구성으로 방호복의 중량을 줄이면서 착용자로 하여금 유연성과 동작성을 향상시켜 임무수행과 안전성을 높일 수 있는 방호복을 개발하고자 하였다. 1) Para-aramid(내 충격열) + Flex-felt(충격 에너지 흡수) + Para-aramid(backface Polyethylene film(에너지 분산 극대)+Para-aramid(내 마찰열, backface순으로 소재를 배열함으로써 기존의 Para-aramed 36겹에 대하여 Para-aramid13겹, Polyethylene film 13겹, 그리고 펠트 1겹으로 동일한 방호성능을 얻었다. 2) 새로운 소재 구성 방법 에 의 한 방탄소재는 동일한 방호성능을 갖는 기존의 소재 구성 방법 에 따른 방탄소재 보다 중량에서 34-l9% ,더 가벼운 것으로 나타나 방호복 구성시 유연성이나 동작성에 유리 할 것으로 사료된다. 3) NIJ-STD-0101.03에서 의 Armor type II에 해당하는 시편 I의 방호한계속도로 구한 운동 에너지량은 154.4J Armor type III-A에 해 당하는 시편II의 방호한계속도로 구한 운동 에너지 량은 183.0J로 나타나 두 시편 모두 5m의 거리에서 M16Al지뢰의 0.032~0.044g사이 의 파편에 대해서 50%의 관통확률을 갖는 것으로 나타났다.

• Journal of the Korean Society for Precision Engineering
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• v.20 no.12
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• pp.126-134
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• 2003

In order to investigate the effect of surface treatment in Aluminium alloy and Titanium alloy which are used to armor material during ballistic impact, a ballistic testing was conducted. Anodizing was used to achieve higher surface hardness of Aluminium alloy and Iron plating in PVD(Physical Vapor Deposition) method was used to achieve higher surface hardness of Titanium alloy. Surface hardness test were conducted using a Micro victor's hardness tester. Ballistic resistance of these materials was measured by protection ballistic limit(V-50), a statical velocity with 50% probability penetration. Fracture behaviors and ballistic tolerance, described by penetration modes, are respectfully observed from the results of V-50 test and Projectile Through Plates (PTP) test at velocities greater than V-50. PTP tests were conducted with 0$^{\circ}$obliquity at room temperature using 5.56mm ball projectile. V-50 tests were conducted with 0$^{\circ}$obliquity at room temperature with projectiles that were able to achieve near or complete penetration during PTP tests. Surface hardness, resistance to penetration. and penetration modes of surface treated alloy laminates are compared to those of surface non-treated alloy laminates. A high speed photography was used to analyze the dynamic perforation phenomena of the test materials.

• Journal of the Korea Society for Simulation
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• v.30 no.1
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• pp.55-63
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• 2021

As a study on ballistic protection performance of a weapon system that is used in combat simulation, this paper aims to propose an improvement effect of the ballistic protection performance varying with incident angle of a bullet. For this, live-fire ballistic tests were performed to determine either complete penetration(CP) and partial penetration(PP) of three types of general armor plates made of uniformly rolled steel plates against a small caliber threat using 5.45 mm bullets with various speed. The major test parameter was the material of the weapon system and incident angle of the bullet with the target. Further, to quantitatively analyze the ballistic protection performance, three existing measurement methods were used for ballistic limit velocity. The test results showed that the ballistic protection performance with the incident angle of 30 degrees was 4% to 14% varying with the material of the armor plates greater than that of 0 degrees, which was approximately 1.1 times the performance improvement on average when compared to the conventional angle of incidence of the 0 degree. Those test results are expected to contribute to developing a more realistic combat simulation addressing the parameter improving the ballistic protection performance of an armor plate.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.24 no.6
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• pp.691-697
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• 2011

In this study, the vessel collision protective structure and the vessel were modeled numerically and the quasi-static collision analysis was performed to evaluate the maximum protection capacity. In the modeling process of protective structure, the nonlinear behaviors of structure and the supporting conditions of ground including pull-out action were considered. In that of collision vessel, the bow of vessel was modeled precisely, because of the nonlinear behaviors were concentrated on it. For the efficient analysis, the mass scaling scheme was applied, also. To evaluate the differences and efficiency, the dynamic analyses were performed for the same model, additionally. Based on the obtained energy dissipation curves of the structure and the vessel, the moment that the collision force affected to the bridge substructures was determined and the maximum allowable collision velocity was evaluated. Because of the energy dissipation bound can be recognized clearly, this scheme can be used efficient in engineering work.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2003.10a
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• pp.210-210
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• 2003

• Journal of the Korea Academia-Industrial cooperation Society
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• v.22 no.6
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• pp.573-582
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• 2021

In this study, a series of processes for evaluating the effective protection against barriers that should be equipped in institutions that perform reliability tests on high-risk ammunition, such as high-explosive ammunition, were introduced. The impact that high-explosive bombs can have on personnel includes damage to the eardrum and lungs caused by explosion overpressure and penetrating wounds that can be received by fragments generated simultaneously with the explosion. Therefore, a high-explosive with COMP B explosives as its contents were set up, and an explosion protection theory investigation to calculate the degree of damage, numerical calculations and simulations were performed to verify the protection power. A numerical calculation revealed the maximum explosion overpressure on the protective wall when the high-explosive exploded and the penetration force of the fragment against a 50 mm-thick protective wall to be 77.74 kPa and 41.34 mm, respectively. In the simulation verification using AUTODYN, the maximum explosion overpressures affecting the firewall and personnel were 56.68 kPa and 18.175 kPa, respectively, and the penetration of fragments was 35.56 mm. This figure is lower than the human damage limit, and it was judged that the protective power of the barrier would be effective.

• Korean Security Journal
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• no.61
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• pp.39-57
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• 2019

The executive authority of the Ministry of Public Administration and Security on the 'management of security of the government complexes' is not sufficiently secured only with the organization law, the Government Organization Act. It is needed to establish an administrative actions law, an individual law that sets detailed contents and limitations of the executive authority to be stipulated. The current regulation, Regulation on the Management of the Government Complexes which is a Presidential Decree, is a legal decree that lacks a legal basis. The decree does not match with the current constitutional framework and raises the issue of its legality. The regulation may have the characteristics as a public property management law so far as it stipulates such matters as supply and maintenance management for the complexes, acquisition and disposition of complexes, facilities management of complexes, etc. However, the regulation includes high authority actions by an administrative organization, such as facilities security and order maintenance including restriction and control of access. This makes the regulation have the characteristics of a public property policy act as well. To supplement the legal framework for this situation, it is needed to level up some of the provisions relating to protection and security management to the level of an act as they stipulate high authority actions by an administrative organization. Other matters in the Regulation on the Management of the Government Complexes such as provisions relating to supply and allocation of complexes, etc. may be maintained as they are. In addition, the protection officers (general service official) does not own legal authority and have limitations on securing the capability to deal with the situations on implementing the on-site protection duty. Therefore, it is needed for the protection officers to secure protection duty-related authority by stipulating in a law. The main contents of the law on the protection and security of the government complexes may be those matters providing reservations on the implementations of laws. These may include the limitation of rights of and charging obligations on the people such as restricting the actions of personnel in the complex, rights and obligations of protection personnels relating to their duties, use of weapons, training of protection personnel, penal provisions, etc. These legal reservations should be included in an individual act.

• Journal of the Korea Institute of Building Construction
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• v.13 no.5
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• pp.465-473
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• 2013

Concrete is an outstanding material in terms of its impact and blast resistance performance. However, there a limitation of concrete is its risk of collapse due to the brittle failure and spalling. Increasing the thickness of members was used as a method to enhance the protective performance of concrete, despite the resulting inefficient space. To solve this problem, different types of fiber reinforced concrete were developed. Recently, another type of fiber reinforced concrete is also being developed and applied as a material that offers protection against impacts and blasts by increasing the flexural toughness of concrete. In this study, the test was conducted to evaluate the impact resistance performance of fiber reinforced concrete and mortar according to impact of high-velocity projectile. A concrete T-wall was also tested to evaluate its protective performance from fragment by 155mm-thick artillery shell. The test results revealed that improving flexural strength through fiber reinforcement inhibited cracks and spalling of rear, and spalling of front by high-velocity impact. As such, it is expected to improve the protective performance of the T-wall and reduce the thickness of the member.

• Journal of the Korea Institute of Military Science and Technology
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• v.19 no.5
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• pp.629-637
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• 2016

This paper presents a ballistic limit velocity measurement using the support vector machine that classifies two classes, the partial penetration and the complete penetration, by generating a linear separating hyperplane that equally divides the classes. For the ballistic limit velocity measurement, the previous methods(MIL-STD-662F and NIJ-STD-0101.06) have required a large number of experiments that caused high cost and time. However, the proposed method is not only flexible, requiring 0.85 ~ 4.8 times fewer experiments but also reliable, providing less than 2 % difference in results compared to the previous methods. For its validation, live fire experiments were conducted using various thickness SS400 iron plates as a target and two different types of live bullets such as 5.56 mm M193 and 7.62 mm M80.