PELE의 경사진 충격에 따른 파괴 메커니즘에 대한 연구

조종현,이영신,Jo, Jong-Hyun,Lee, Young-Shin 한국군사과학기술학회 2012 한국군사과학기술학회지 Vol.15 No.5

Penetrator with enhanced lateral effect(PELE) is a newconcept projectile, without dynamite and fuze. It consists of high-density jacket, closed at its rear end and filled with a low-density filling material. To study the explosion characteristics of PELE, by AUTODYN-3D code, the calculation models of projectile body and bullet target are established and the process of penetrating aluminum-2024 alloy target of PELE is simulated, and the scattering characteristics after penetrating aluminum-2024 alloy target of PELE are studied by different initial velocity. The explicit finite element analysis of PELE fragmentation was implemented with stochastic failure criterion in AUTODYN-3D code. As expansion of filling, the fragments were obtained velocities and dispersed laterally and further more enhancing the damage area largely. The number and shape of the PELE fragments were different depend on impact velocity and incidence angle of filling which fragment generated during penetration and lateral dispersion process.

SPH 를 이용한 알루미늄 판의 파편운 정량적 해석

조종현(Jong-Hyun Jo),이영신(Young-Shin Lee) (사)한국CDE학회 2013 한국 CAD/CAM 학회 학술발표회 논문집 Vol.2013 No.1

This paper present numerical analysis of debris clouds due to aluminum spheres impacting aluminum plates. The explicit analysis program AUTODYN-2D is used in this work. Smoothed particle hydrodynamics(SPH) is a numerical analysis method mainly used in hypervelocity impact analysis. The particle analysis using SPH can give clear shape and result especially regarding the fragment movement. The objective of numerical analysis was to determine the expansion characteristics of debris clouds produced by hypervelocity impacts under different initial conditions such as initial velocity, incidence angle of the projectile, and thickness of target plate. In the condition of oblique impact, the debris cloud deflects from the main axis, and the deflection was decreased as the incident angle increased. The debris cloud could not be formed as the incident angle exceeds some definite value(about 60°). The numerical results show that the dimensions of the granules of the debris cloud was decreased when impact velocity increases, and increases with the thickness of the plate. This represents the relationship among the projectile velocity, plate thickness and grinding in the condition of hypervelocity impact.

폴리카보네이트 판의 경사충격에 의한 도비 거동 수치연구

조종현(Jong-Hyun Jo),이영신(Young-Shin Lee) (사)한국CDE학회 2013 한국 CAD/CAM 학회 학술발표회 논문집 Vol.2013 No.1

In this study, the numerical simulation using AUTODYN-3D program was investigated angle trajectory prediction for inclined impacts of projectiles. The penetration and perforation of polycarbonate plate by 7.62 mm projectile was investigated numerically. The characteristic structure of the projectile’s trajectory in the polycabonate plates was studied. Two combined failure criteria were used in the target plate, and the target plate was modeled with the properties of polycarbonate for simulating the ricochet phenomenon. The effect of the angle of inclination on the trajectory and kinetic energy of the projectile were studied. The dynamic deformation behaviors tests of polycabonate were compared with numerical simulation results which can be used as predictive purpose. From the simulation, the ricochet phenomenon was occured for angles of inclination of 0°≤ ? ≤ 20°. The projectile perforated the plate for ? ≤ 30°, thus defining a failure envelope for numerical configuration. The numerical analyses are used to study the effect of the projectile impact velocity on the depth of penetration (DOP). It can be observed that the residual velocities were almost linear relative to penetration velocities. It means that polycarbonate has high resistance at higher velocities.

치료적 악기연주의 효과 증진을 위한 디지털 우쿠렐레와 모바일 재활 콘텐츠 개발

조종현(Jong-Hyun Jo),여정진(Jeong-Jin Yeo),양윤석(Yoonseok Yang) 대한전자공학회 2016 대한전자공학회 학술대회 Vol.2016 No.6

침의 염증 제어 기전에 관한 최근 견해: 최신 연구를 바탕으로

조종현 ( Jong Hyun Jo ),안성훈 ( Seong Hun Ahn ),손인철 ( In Chul Sohn ) 대한경락경혈학회 2008 Korean Journal of Acupuncture Vol.25 No.2

Objectives: The acupuncture has been in the classic arsenal of Oriental medicine over inflammatory diseases. Its physiological mechanism is not fully understood but being known better everyday. We reviewed several papers to describe current concepts over anti-inflammatory mechanism of acupuncture. Methods: Some computerized Literature searches were done using the key words of `acupuncture` AND `Anti-inflammatory` in Medline via Pubmed between March 2007 and December 2007. Only rationally-designed studies were picked among practically associated materials. A well-known hypothesis on acupunctural physiology was adapted for integration. Result: 18 studies were selected. 17 studies were Laboratory experiment and 1 was a clinical study. Data was classified into some comprehensive categories. Author`s opinion was added at the end of each category. Study results supported the hypotheses on acupunctural physiology; Acupuncture has some influences on autonomic nerve system(ANS). And it stimulates several receptors from target cells Like macrophage, and finally inhbits cytokines Like TNF-α, IL-1β andIL-10 which are inflammation-mediated. Acupuncture increases the opioid releasing therefore relieves inflammation. And acupuncture inhibits cyclooxgenase(COX) but its mechanism is controversial until now. Conclusion: Current concepts over anti-inflammatory mechanism of acupuncture are as follows. Acupucture suppresses inflammation by stimulation of ANS, increasing of opioid releasing and inhibition of COX. But more studies are needed to fully describe the anti-inflammatory effect of acupuncture.

축성 척추관절염 환자에서 4주간 침 시술의 효과와 안전성에 관한 무작위, 이중맹검, 대조군 연구

조종현 ( Jong Hyun Jo ),권정주 ( Jeong Ju Kweon ),송윤경 ( Yun Kyung Song ),임형호 ( Hyung Ho Lim ),백한주 ( Han Joo Beak ) 한방재활의학과학회 2012 한방재활의학과학회지 Vol.22 No.4

Objectives : To evaluate the clinical effectiveness and safety of acupuncture in patients with axial spondyloarthritis. Methods : A randomized, double-blinded, sham controlled, parallel group trial. Random allocation was done under blocked randomization with allocation concealment by opaque sequentially numbered sealed envelopes. Participants Conducted between November 2011 and February 2013, participants were recruited from the outpatients of department of rheumatology in Gil hospital who were diagnosed with axial spondyloarthritis by rheumatologists under ASAS(assessment in ankylosing spondylitis) classification criteria. Intervention Active acupuncture and sham control group were made. Each participant in that group took 8 sessions of acupuncture in 4 weeks, twice per a week. Usual medical treatments were attained independently during whole session. Results : 10 participants were analyzed. 6 were allocated in treatment group and 4 went sham control group. Acupuncture showed significant reduce on visual analogue scale of low back pain at 4th week.(p=0.021) but failed to show superiority on control. Harms 1 participant(16.5%) from acupuncture group complained of mild local pain. Conclusions : Acupuncture is able to reduce low back pain with axial spondyloarthritis but it could be placebo effect.

분절형 텅스텐 관통자의 초고속 관통특성에 관한 연구

조종현(Jong Hyun Jo),이영신(Young Shin Lee),김재훈(Jae Hoon Kim),배용운(Yong Woon Bae) 대한기계학회 2013 大韓機械學會論文集A Vol.37 No.8

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°, 30°, 45° 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. This study aimed to investigate the penetration characteristics of a segmented penetrator with normal and inclined angles. The length to diameter ratio (L/D) of the segmented penetrator was varied as 1.0, 0.5, and 0.25. Moreover, impact velocities of 1.5, 2.0, and 2.5 km/s and inclination angles of 15°, 30°, and 45° were successively applied. The AUTODYN-3D code was used to simulate the penetration performance of the segmented penetrator. The results show that the penetration performance of the segmented penetrator with steel plates was obviously higher than that of the corresponding continuous penetrator with steel plates. The outstanding penetration performance of the segmented penetrator can be observed when the impact velocity was 2.0 km/s and L/D = 1. In this case, the penetration performance of the segmented penetrator was 7% higher than that of the corresponding continuous penetrator. This trend was attributable to the interaction between the reactive plate and the projectile. The extent of the interaction relies on the relative velocities of the plate and projectiles, inclination angle, and number of segmented penetrators. It was proven that the penetration performance of the segmented penetrator can be improved by increasing the impact velocity, number of segmented penetrators between segments, and penetrator length.

다층 강재 방호판의 초고속 충격 파괴거동해석

조종현(Jong Hyun Jo),이영신(Young Shin Lee),김재훈(Jae Hoon Kim),배용운(Yong Woon Bae) 대한기계학회 2013 大韓機械學會論文集A Vol.37 No.6

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. New warheads are designed and developed to be highly lethal when used as part of ballistic missile payloads. There are many trades associated with the design of a central warhead core, mainly dealing with the projectiles or penetrators. Obviously, a payload-type configuration is very susceptible to kills from one projectile because of the high impacts required for bomblet or submunition payloads. Based on these requirements, the optimum kill vehicle configuration will have the smallest mass and relative velocity that will kill all the submunitions. The designs of the penetrator shape and size are directly related to the space and weight of the warhead. The shape, size, L/D, penetrator material, and manner in which they are inserted inside the surrounding explosive segments are critical in achieving successful penetrator design. The AUTODYN-3D code was used to study the effect of penetrator penetration. The objective of numerical analysis was to determine the penetration characteristics of the penetrator produced by hypervelocity impacts under different initial conditions such as initial velocity, shape, and L/D of the penetrator.

금속 표적체에 대한 분절형 관통자의 초고속 관통특성에 관한 연구

조종현(Jong-Hyun Jo),이영신(Young-Shin Lee),김재훈(Jae-Hoon Kim),배용운(Yong-Woon Bae) (사)한국CDE학회 2013 한국 CAD/CAM 학회 학술발표회 논문집 Vol.2013 No.1

The purpose of this paper was to investigate the penetration characteristics of segmented penetrator against normal plates. The length to diameter ratio(L/D) of the segmented penetrator was 1.0, 0.5 and 0.25 respectively. Besides, 1.5, 2.0 and 2.5 km/s impact velocities were applied respectively. The AUTODYN-3D code was used to simulate the penetration performance of the segmented penetrator. The results show that the penetration performance of the segmented penetrator with steel plates was obviously higher than that of the corresponding continuous penetrator with steel plates. The outstanding penetration performance of the segmented penetrator can be observed when the impact velocity was 2.0 km/s and L/D = 1. In this case, the penetration performance of the segmented penetrator was 7 % higher than that of the corresponding continuous penetrator. This trend was due to the interaction between the reactive plate and projectile. The extent of the interaction relies on the relative velocities of the plate and projectiles, the plate thickness and number of the segmented penetrator. The penetration performance of the segmented penetrator can be improved through increasing the impact velocity and number of the segmented penetrator between segments and penetrator length.

텅스텐 원형 관통자의 관통특성에 관한 연구

조종현(Jong Hyun Jo),이영신(Young Shin Lee),김재훈(Jae Hoon Kim),배용운(Yong Woon Bae) 대한기계학회 2013 大韓機械學會論文集A Vol.37 No.9

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≤4 에서의 초기 충격속도 증가는 잔류질량과 잔류속도를 감소시킨다. The design of missile require extremely small warheads that must be highly efficient and lethal. The penetration characteristics of each penetrator and the total number of penetrators on the warhead are obvious key factors that influence warhead lethality. The design of the penetrator shape and size are directly related to the space and weight of the warhead. The design of the penetrator L/D was directly related to the space and weight of the warhead. L and D are the length and the diameter of the projectile, respectively. The AUTODYN-3D code was used to study the effect of penetrator penetration. The objective of numerical analysis was to determine the penetration characteristics of penetrator produced by hypervelocity impacts under different initial conditions such as initial velocity, obliquity angle and L/D of penetrator. The residual velocity and residual mass were decreased with increasing initial impact velocity under L/D≤4.