• Journal of Aerospace System Engineering
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• v.9 no.2
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• pp.7-12
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• 2015

In this paper, we report a non-explosive separation device for a small satellite which utilize a shape memory alloy actuator and spring clamp. In order to increase the preload, the proposed device employs spring clamp that can generate high toque when the shape memory alloy actuator makes the cylinder key unlatch a holding ball effectively. Owing to simple design of separation device configuration, we could obtain good repeatability(up to 30 times activation). Conclusively, we could develop a non-explosive separation device which can reliably activate within 1.2 sec under high preload(up to 300kgf).

• Korean Journal of Construction Engineering and Management
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• v.5 no.4 s.20
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• pp.130-138
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• 2004

The demolition works of high building in korea are expecting to increase rapidly in the near future, and its general demolition methods can be divided into mechanical demolition method and explosive demolition method. The selection of the right demolition method relies on many variable elements according to environmental and geographical elements. But, generally, the most important element of those is a economical profit. Accordingly, This study estimates each demolition cost dividing into mechanical demolition method and explosive demolition method of high building in city. And the estimating of the demolition cost makes it possible to do comparative analysis for the economical efficiency of each method more objectively than any other selective elements. Also, the analysis for the economical efficiency helps to forecast the activated time of the explosive demolition method in domestic.

• Transactions of the Korean Society of Mechanical Engineers
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• v.16 no.6
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• pp.1108-1114
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• 1992

In this paper results from experimental studies on the line wave detonation of explosive welding were presented. Using the ultra high speed comera, the ling wave generation during the bonding, process of composite materials was observed with an equilateral triangle lens. Experimental results confirmed the line wave formation of the shock front. And the results indicated the effectiveness of the ling wave detonation method in the explosive welding of similar or dissimilar metals.

• Metals and materials international
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• v.24 no.6
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• pp.1327-1332
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• 2018

In this study, a novel approach to the explosive synthesis of titanium carbide (TiC) is discussed. Nonstoichiometric $TiC_x$ powder was produced via the underwater explosion of a Ti powder encapsulated within a spherical explosive charge. The explosion process, bubble formation, and synthesis process were visualized using high-speed camera imaging. It was concluded that synthesis occurred within the detonation gas during the first expansion/contraction cycle of the bubble, which was accompanied by a strong emission of light. The recovered powders were studied using scanning electron microscopy and X-ray diffraction. Submicron particles were generated during the explosion. An increase in the carbon content of the starting powder resulted in an increase in the carbon content of the final product. No oxide byproducts were observed within the recovered powders.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2006.04a
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• pp.123-126
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• 2006

Reduction kinetics and intermediates behaviour of three high explosives (HMX, RDX, and TNT) were studies in batch reactors using either nano or micro size zero valent iron(ZVI) as reducing agent. The kinetics constants normalize to the mass of iron($k_M$) or to the surface area ($k_{SA}$) were measured and compared along with the changes of intermediate concentrations of each explosive. Results showed that $k_M$ and $k_{SA}$ values neither correlated each other nor explained the behaviour of intermediates of each high explosive in the batch reactor, in which initial intermediates decreased rapidly with nano ZVI treatment whereas the intermediates accumulated and stayed longer in the micro ZVI treated reactor.

• 한국연소학회:학술대회논문집
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• 2012.04a
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• pp.275-278
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• 2012

We investigate the interaction between the propagation of detonation and inserted gaps in the high explosive. The Eulerian-based multi-material simulation code validated through comparison with experimental results was used. A series of gap materials is used to understand the detonation propagation characteristic in the presence of multiple gaps.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.21 no.1
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• pp.55-61
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• 2011

Cyclonite is a white powder and is very explosive. It can cause seizures (a problem of the nervous system) in human and animals when large amounts are inhaled or eaten. Research papers for workers exposure assesment of the cyclonite are very a few in the world. A field study was conducted at explosive compounds and bomb manufacturing companies to evaluate workers exposure to cyclonite. The airborne average concentration of cyclonite in explosive compounds manufacturing company was $4.10{\mu}g/m^3$(range: ND - $59.92{\mu}g/m^3$), and that of cyclonite in bomb manufacturing company was $31.49{\mu}g/m^3$(range: ND - $291.41{\mu}g/m^3$). Package process and assembly process in both companies were considered the high potential of exposure to cyclonite. Even though all airborne concentrations of cyclonite were lower than occupational exposure standard (MOEL: $500{\mu}g/m^3$), exposure to cyclonite can also occur through dermal contact during manufacture, handling, and clean-up of cyclonite. So control measures for protecting skin absorption of cyclonite were needed for preventing adverse health effect by cyclonite exposure.

• Explosives and Blasting
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• v.40 no.2
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• pp.15-24
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• 2022

Recently, the demand of demolition for the unnecessary industrial structure is increasing due to deterioration tendency and the issue of demolition is becoming a major highlight. The restoration of the dismantled industrial site to its original natural state was currently underway. This execution case was intented to describe an application of the felling method one of the explosive demolition method to the demolition of the industrial stack. This stack was 150m high, a composite structure in which the outer wall of the stack was a reinforced concrete shell structure and internal stovepipe was a steel shell structure. As as result of the explosive demolition, the stack had collapsed precisely according to estimated direction. And the explosive demolition was completed without causing any damage to surrounding facilities.

• Tunnel and Underground Space
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• v.22 no.2
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• pp.157-161
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• 2012

ZnO-98% and $Ga_2O_3$-2% powder were consolidated by shock compaction technique, which uses a high performance explosive. The microstructural and electrical characteristics of $ZnOGa_2O_3$ compact with density of 97% and hardness of 220~250 $H_v$ were investigated using SEM (Scanning Electron Microscope) and X-ray diffraction analysis, respectively. In the microstructures of the compact, there were no visible cracks at most of the surface areas, and interparticle bonding between powder particles was confirmed. The broadened peaks were detected due to deformation of crystallited size and high electric resistances were confirmed due to increased grains because of shock energy with a high pressure and high velocity.

• Journal of the Society of Naval Architects of Korea
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• v.57 no.6
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• pp.322-330
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• 2020

This study deals with underwater explosion (UNDEX) characteristics of various non-explosive underwater shock sources for the development of non-explosive underwater shock testing devices. UNDEX can neutralize ships' structure and the equipment onboard causing serious damage to combat and survivability. The shock proof performance of naval ships has been for a long time studied through simulations, but full-scale Live Fire Test and Evaluation (LFT&E) using real explosives have been limited due to the high risk and cost. For this reason, many researches have been tried to develop full scale ship shock tests without using actual explosives. In this study, experiments were conducted to find the characteristics of the underwater shock waves from actual explosive and non-explosive shock sources such as the airbag inflators and Vaporizing Foil Actuator (VFA). In order to derive the empirical equation for the maximum pressure value of the underwater shock wave generated by the non-explosive impact source, repeated experiments were conducted according to the number and distance. In addition, a Shock Response Spectrum (SRS) technique, which is a frequency-based function, was used to compare the response of floating bodies generated by underwater shock waves from each explosion source. In order to compare the magnitude of the underwater shock waves generated by each explosion source, Keel Shock Factor (KSF), which is a measure for estimating the amount of shock experienced by a naval ship from an underwater explosionan, was used.