• 한국군사과학기술학회지
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• 제20권4호
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• pp.543-550
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• 2017

Various chemical properties including density and heat of formation of 1-substitued trinitroimidazoles (TNIs) were estimated by using density functional theory (DFT). Using chemical properties estimated by DFT, explosive performance and sensitivity of 1-substitued TNIs were analyzed by following the ADD Method-1 procedure. The results were displayed on two-dimensional performance-sensitivity plot, and were compared with those of explosive molecules commonly used in many military systems. Different 1-substituents of TNI made that both explosive performance and impact sensitivity were changed significantly. Methyl substituted TNI became moderately insensitive and slightly less powerful. Amino, fluoro, picryl, and difluoroamino substituted TNIs were highly powerful like RDX and HMX, but greatly sensitive. Nitro substituted TNI was predicted to be extremely sensitive to be handled as a secondary explosive.

• 한국추진공학회지
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• 제21권1호
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• pp.104-111
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• 2017

탄두 신관에 사용되는 길이 25.4 mm, 직경 8.0 mm이고 행정길이 25.4 mm 이상에 대해 4.5 kgf의 추력을 제공하는 화약 벨로우즈를 새로이 개발하였다. BP/MTV 조성의 새로운 가스발생기를 개발하였으며, 화약 벨로우즈 작동시 압축되는 스프링의 길이를 측정하는 위력시험장치도 고안하였다. 새로 개발된 화약 벨로우즈가 요구조건을 만족하는지 검증하기 위해 감도시험과 위력시험을 수행하였다. 시험결과 새로 개발한 화약 벨로우즈는 요구조건을 충족하였으며, 탄두용 신관에 적용이 가능하다.

• Steel and Composite Structures
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• 제31권3호
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• pp.233-242
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• 2019

Early detection of damage bonding state such as insufficient bonding strength and interface partial contact defect for the explosive clad pipe is crucial in order to avoid sudden failure and even catastrophic accidents. A generalized and efficient model of the explosive clad pipe can reveal the relationship between bonding state and vibration characteristics, and provide foundations and priory knowledge for bonding state detection by signal processing technique. In this paper, the slender explosive clad pipe is regarded as two parallel elastic beams continuously joined by an elastic layer, and the elastic layer is capable to describe the non-uniform bonding state. By taking the characteristic beam modal functions as the admissible functions, the Rayleigh-Ritz method is employed to derive the dynamic model which enables one to consider inhomogeneous system and any boundary conditions. Then, the proposed model is validated by both numerical results and experiment. Parametric studies are carried out to investigate the effects of bonding strength and the length of partial contact defect on the natural frequency and forced response of the explosive clad pipe. A potential method for identifying the bonding quality of the explosive clad pipe is also discussed in this paper.

• 화약ㆍ발파
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• 제39권1호
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• pp.22-35
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• 2021

산업용 플랜트의 기능적·노후화에 따른 해체 수요가 증가하고 있으며, 시간적·공간적 환경위해요소를 최소화하기 위해 발파해체공법 또는 기계식 해체공법 및 발파해체공법을 혼용한 해체공법의 적용이 증가하고 있다. 본 시공사례에서는 철근콘크리트 구조방식으로 건설된 플랜트 기초를 해체하기 위해 발파해체공법을 적용하였다. 그 결과로서 플랜트 기초의 적정한 목표 파쇄가 이루어졌으며, 주변 시설물에 대한 피해가 없음을 확인하였다.

• Nuclear Engineering and Technology
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• 제55권6호
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• pp.1988-1993
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• 2023

This experimental study investigated the effect of silica fume mixed in concrete blocks on laser-induced explosion behavior. We used a 5.3 kW fiber laser as a thermal source to induce explosive spalling on a concrete surface blended with and without silica fume. An analytical approach based on the difference in the removal rate and thermal behavior was used to determine the effect of silica fume on laser-induced explosive spalling. A scanner was employed to calculate the laser-scabbled volume of the concrete surface to derive the removal rate. The removal rate of the concrete mixed with silica fume was higher than that of without silica fume. Thermal images acquired during scabbling were used to qualitatively analyze the thermal response of laser-induced explosive spalling on the concrete surface. At the early stage of laser heating, an uneven spatial distribution of surface temperature appeared on the concrete blended with silica fume because of frequent explosive spalling within a small area. By contrast, the spalling frequency was relatively lower in laser-heated concrete without silica fume. Furthermore, we observed that a larger area was removed via a single explosive spalling event owing to its high porosity.

• 한국안전학회지
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• 제8권3호
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• pp.91-104
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• 1993

This paper is on the current and prospect of the most advanced explosive technics, special explosive technics. Futhermore, utmost needed and utmost centered interesting basic theory, struction explosive demolition is descirbed with counter Plan on the Problems of carrying out example and cuf out of it. Specified description noted on the four pollution especially noisy vibration, dust and disperse pollution with comprehensive counter plan. Although it has some insufficiency. I expect my paper will be to advance the explosive technics.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2006년도 추계 학술발표회 논문집
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• pp.797-800
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• 2006

Normally, Structural light-weight aggregate concrete(LWC) has been main used in high rise building with the object of wight loss. In spite of LWC have the advantage of light-weight, limit the use of strength restrictions by reason that explosive spalling in fire. Especially, LWC is occurred serious fire performance deterioration by explosive spalling. Thus, this study is concerned with fire performance of LWC for the purpose of using PP fibers prevent to explosive spalling. From the experimental test result, LWC is happened explosive spalling.

• 한국콘텐츠학회논문지
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• 제14권12호
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• pp.775-784
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• 2014

본 연구는 대학생들의 부정적 정서가 자살생각에 미치는 영향에서 성별을 통해 폭발적 행동이 매개된 조절효과를 검증하기 위해 수행되었다. 이를 위해 대학생 644명(남자 322명, 여자 322명)을 대상으로 우울, 불안, 폭발적 행동 및 자살생각을 조사하였고, 매개된 조절효과는 위계적 회귀분석과 경로분석을 통해 분석하였으며, 단순기울기검정 결과를 도식으로 제시하였다. 연구결과, 첫째, 부정적 정서, 폭발적 행동과 자살생각 간에 모두 유의한 정적 상관관계가 나타났다. 둘째, 부정적 정서와 자살생각 간의 관계에서 성별의 조절효과는 유의하였다. 셋째, 부정적 정서와 자살생각 간의 관계에서 폭발적 행동의 매개효과는 유의하였다. 넷째, 폭발적 행동과 자살생각 간의 관계에서 성별의 조절효과는 유의하였다. 이러한 연구결과를 바탕으로 성별에 따른 부정적 정서와 폭발적 행동이 자살생각의 증진에 미치는 영향에 대한 시사점 및 후속연구에 대한 제언을 논의하였다.

• 화약ㆍ발파
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• 제17권4호
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• pp.8-17
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• 1999

Unfortunately leaks occur in heat exchangers periodically, usually at the tube to tubeplate joint. The usual method of repair is to plug off the defective area and isolate the tubes of concern from the circuit. If the leaks continua the thermal capacity of the units is progressively reduced and for this reason the alternative of using an internal bridging sleeve has been examined. This paper discusses the overall development activities that has been found necessary to bring this repair procedure to a successful conclusion for use on the nuclear steam generator. In this work we have investigated optimum explosives and explosive quality, explosive sleeving's thickness, the design of sheath stress relieving heat treatment pull-out load, hydraulic leakage, stress corrosion cracking properties. The results obtain are as follows : (1) The optimum explosives and explosive qualities are PETN and about 15~40 gr/ft of explosive sleeving in nuclear steam generator. (2) Explosive sleeving's thickness is 1.1~l.4mm, If groove of 0.35mm formed in sleeve outside existed, For the hydraulic leakage is go up, explosive sleeving of formed groove are applicate tube and turnplate. (3) If the stress relieving heat treatment are experiment in $750^\circ{C}$, $850^\circ{C}$, 15 minutes Pull-out strength of sleeving 1,500~2,300kg, hydraulic leakage is $250kg/cm^2$.

• 한국전산구조공학회논문집
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• 제30권2호
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• pp.145-151
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• 2017

콘크리트 구조물 또는 암석의 해체 공정에서 소음, 진동, 분진 등의 발생을 초래하는 기존의 발파공법을 대신하여 비폭성 파쇄제의 이용을 고려할 수 있다. 본 연구는 유한한 정사각형 콘크리트 구조물을 대상으로 하여 비폭성 파쇄제의 팽창이 준정적으로 균열을 발생, 진전시키는 과정을 유한요소해석으로 예측하고 기존 문헌에 보고된 실험결과와 비교함으로써 해석결과의 정확성을 검증하였다. 또한 비폭성 파쇄제 및 천공 홀의 배치에 따른 영향을 최소요구팽창압 관점에서 분석하였다. 더 나아가서 비폭성 파쇄제가 채워지지 않은 천공 홀이 비폭성 파쇄 공정에 미치는 영향을 분석하고, 분리 조각의 수를 증가시켜 파쇄도를 향상시키기 위한 비폭성 파쇄제 및 천공 홀의 효과적인 배치에 대하여 고찰하였다.