• 한국군사과학기술학회지
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• 제23권4호
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• pp.355-362
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• 2020

EFP composed of explosive, charge and liner generally penetrates standoff a target by Monroe effect. Its performance highly depends on penetrator characteristics and flight stability. Penetration ability can be dramatically reduced when the penetrator reaches the target with AOA, even if the penetrator has high kinetic energy and L/D ratio. Therefore, it is important to research not only penetrator characteristics and but also flight stability. In this work, the effect of liner shape on penetrator characteristics was examined using free flight test and numerical tools. It was found that tip velocity of penetrator was increased with decreasing liner thickness. It was also found that thicker liner had higher static margin leading to better flight status.

• 한국군사과학기술학회지
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• 제20권3호
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• pp.384-392
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• 2017

A linear explosively formed penetrator(LEFP) is a modification of the explosively formed penetrator(EFP). An EFP is axisymmetric and has a dish-shaped liner while LEFP has a rectangular-shaped liner with curved cross section. Upon detonating LEFP forms laterally wide projectile like blade, leaving a long penetration hole on the target. On the other hand, a long-rod tungsten heavy alloy(WHA) penetrator is one of the major threats against most of the ground armored vehicles. In this paper, the feasibility of using an LEFP in protecting against a long-rod WHA penetrator by colliding LEFP into the threat was investigated through a set of numerical simulations. In this study, a scale-down WHA penetrator with length to diameter ratio(L/D) of 10.7 and 7.0 mm diameter was used to represent a long-rod WHA penetrator. LS-DYNA and Multi-Material ALE technique were employed for the simulation. For estimation of the protection effect by LEFP, residual penetration depths into RHA by the threat were compared according to various impact locations against the threat.

• 한국군사과학기술학회지
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• 제16권3호
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• pp.398-404
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• 2013

The simulation of the ballistic trajectory of penetrator into the spaced multi-layer RC targets is very important to predict the hitting condition in subsequent target. Because of perturbation by lateral load of penetrator caused by asymmetric hitting position between penetrator and steel bar reinforcement, penetrator rotates and deviates from the straight path. Therefore, penetration capability of penetrator is decreased in the subsequent targets. This paper presents the result of the penetration of steel-bar-reinforced concrete target by using the explicit finite element code LS-DYNA. A series of computations is performed and compared to experimental data and the computed results are in good agreement with the experimental results over a wide range of velocities. And then we conduct the simulation according to various RC target hitting condition and impact velocities.

• 한국CDE학회논문집
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• 제18권5호
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• pp.367-373
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• 2013

In this study, the penetration characteristic from the cubic and cylindrical penetrator consisting of tungsten material with the velocity of 2,300 m/s is evaluated and the penetration possibility into the target is confirmed. The design of shape and size of penetrator is directly related to space and weight of the warhead. AUTODYN-3D simulation is used to study the penetration effect of penetrator. The purpose of numerical analysis is to verify the penetration characteristic with various L/D penetrator. The penetration performance of penetrator with identical weight due to the shape is also confirmed. The cylindrical and cubic penetrator has enough penetration energy on constant target body. Because the possibility of 2'nd penetration is important factor after 1'st penetration into target body, residual velocity of residual mass must be existed as much as possible. As geometrical shape ratio increases, penetration performance is confirmed to improve.

• 대한기계학회논문집A
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• 제37권8호
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• pp.953-960
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• 2013

본 논문의 목적은 수직 또는 경사각에 대한 분절형 관통자의 관통특성을 규명하는 것이다. 분절형 관통자의 기하형상비(L/D)는 각 1.0, 0.5, 0.25 이다. 적용된 충격속도와 경사각도는 각 1.5, 2.0, 2.5 km/s 그리고 $15^{\circ}$, $30^{\circ}$, $45^{\circ}$ 이다. AUTODYN-3D code 가 분절형 관통자의 관통성능을 연구하기 위해 사용되었다. 결과는 강판에 대한 분절형 관통자의 관통성능이 해당 연속적 관통자보다 분명하게 높은 특성을 나타냈다. 2.0 km/s 의 충격 속도와 L/D 가 1 일 때, 분절형 관통자의 뛰어난 관통성능을 관찰 할 수 있다. 이 경우 분절형 관통자의 관통성능은 해당 연속적인 관통자보다 7 % 높았다. 이러한 경향은 표적체와 발사체 사이의 상호작용 때문이다. 상호작용의 정도는 표적체와 발사체의 상대속도와 입사각도, 분절형 관통자의 개수에 의존하고 있다. 따라서, 분절형 관통자의 관통 성능은 충격속도의 증가, 관통자의 개수 및 관통길이를 통해서 높일 수 있음이 확인되었다.

• 한국군사과학기술학회지
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• 제5권2호
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• pp.228-238
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• 2002

Using the dynamic explicit program NET3D, oblique impact between long rod penetrator and metallic plate was analyzed. Compared with an experiment and AUTODYN-3D analysis result, the accuracy of NET3D program was examined. It was proved that NET3D program could analyze comparatively exactly oblique impact phenomenon between long rod penetrator and metallic plate. The final deformed configuration of penetrator predicted by NET3D program was more close to experimental result than commercial program AUTODYN-3D. But, in order to increase the reliability of NET3D program in the simulation of tensile fracture phenomenon, the additional research is required.

• 대한기계학회논문집A
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• 제37권9호
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• pp.1083-1091
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• 2013

미사일 설계에서는 매우 효율적이며 치명적인 극히 작은 탄두를 필요로 한다. 탄두에서 각 관통자의 관통성능과 관통자의 총 개수는 탄두 파괴성능에 영향을 미치는 주요 요인이다. 관통자 L/D 의 설계는 탄두의 공간과 중량에 직접적인 관련되어 있다. L 과 D 는 발사체의 길이와 직경이다. AUTODYN-3D code 가 관통자 관통의 영향을 연구하기 위해 사용되었다. 수치해석의 목적은 초기속도, 경사각도, 관통자의 L/D 와 같은 다양한 초기 조건 아래 초고속 충격에 의해 생성되는 관통자의 관통특성을 확인하는 것이다. $L/D{\leq}4$ 에서의 초기 충격속도 증가는 잔류질량과 잔류속도를 감소시킨다.

• 한국군사과학기술학회지
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• 제21권5호
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• pp.563-571
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• 2018

In order to effectively protect a penetrator, the conically shaped protector was proposed and the protection capability was investigated. The collision and penetration of the penetrator with the protector were analyzed using dynamic finite element analysis. The post impact behaviors of the penetrator, i.e., flying velocity and the change of attitude angle, were monitored to investigate the protection capability. The flying velocity and the attitude angle are used to investigate the deviation and the penetration power respectively. The effect of rotation speed of the protector and the collision position on the protection capability is investigated in the viewpoint of deviation and attitude angle when penetrator colliding with our tank.

• 한국분말재료학회지
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• 제11권5호
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• pp.369-375
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• 2004

A new concept of tungsten heavy alloy composite was suggested and manufactured in this study for the kinetic energy penetrator. The composite heavy alloy was composed of two parts, the center was molybdenum added heavy alloy compositions which were designed to promote the self-sharpening effect and outside was conventional heavy alloy in order to sustain the severe stress condition in the muzzle during the firing. The center part showed an intergranular and brittle mode at tungsten/tungsten interfaces by which self-sharpening effect could be activated. On the other hand, that of outside showed conventional ductile fracture mode under high strain rate condition. From the sub-scale penetration test, the depth of penetration in heavy alloy composites showed greater values than those of conventional tungsten heavy alloys. It is suggested that the heavy alloy composite could be considered as one of the future penetrator materials.

• 대한기계학회논문집A
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• 제37권6호
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• pp.761-768
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• 2013

새로운 탄두 기술은 탄도 미사일 적재로부터 높은 파괴성능을 얻기 위해 설계 및 개발 되어왔다. 주로 발사체 또는 관통자를 포함하는 중앙 탄두 코어의 설계와 관련된 많은 연구가 있다. 분명히, 소형 폭탄 또는 자탄 적재 유형 구성은 많은 충격을 요구하기 때문에 하나의 발사체로부터 살상에 매우 취약하다. 이러한 요구사항을 바탕으로 최적의 직격요격체 구성은 모든 자탄을 직격할 수 있는 최소 질량과 상대 속도를 가져야 한다. 관통자 형상과 크기의 설계는 직접적으로 탄두의 공간과 중량에 관련되어 있다. 관통자의 형상, 크기, L/D, 재료 그리고 폭발팩의 구간 내부에 삽입되는 방식은 성공적인 관통자 설계 완성에 중요하다. AUTODYN-3D code 가 관통자의 관통특성을 연구하기 위해 사용되었다. 수치해석의 목적은 초기속도, 관통자의 L/D 및 형상과 같은 다양한 초기 조건 아래 초고속 충격에 의해 생성되는 관통자의 관통특성을 확인하는 것이다.