• Journal of the Korean Society of Safety
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• v.22 no.3 s.81
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• pp.98-104
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• 2007

As the industrial society is highly developing, human need in daily life has also changed drastically. With the introduction of 40 hour working week system, more households enjoy picnics on weekends. More gas accidents take place on Saturdays and on Sundays than any other days of week. In this context, the Institute of Gas Technology Training in Korea Gas Safety Corporation carries out explosion experiment to make trainees to take all possible measure to ensure safe management of gas in the field by fully recognizing the hazards of gas explosion accidents. In this study, the influence of explosion over-pressure caused by the rupture of butane can thrown away after use was calculated by using the Hopkinson's Scaling Law and the accident damage was estimated by applying the influence on the adjacent people into the Probit model. The value of those away from 50 meters from the explosion site was 1.35kPa and the peak overpressure to thoes away from 25 meters directly was 3.2kPa. Those value was input to the PROBIT model, the estimation showed the sante result 0 percent of damage possibility.

• Journal of the Korean Institute of Gas
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• v.21 no.4
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• pp.1-5
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• 2017

Leaking of natural gas, which is mostly methane, in a confined living space creates flammable atmosphere and gives rise to explosion accident. The minimum amount of leaked methane for explosion is highly dependent on the degree of mixing in the confined space. This paper proposes a method for estimating minimum amount of flammable gas for explosion by using Gaussian distribution explosion model(GDEM) and experimental explosion data. The explosion pressure in the confined space can be estimated by assuming the Gaussian distribution of flammable gas along the height of an enclosure and estimating the maximum amount of gas within flammable limits, combustion of the estimated gas with constant volume and adiabatic or isothermal mixing in the confined space. The predicted minimum gas amount for an explosion is tied to explosion pressure that results in a given building damage level. The result shows that very small amount of methane leaking in the confined space may results in a serious gas explosion accident. This result could be applied not only to setting the leak criteria for developing a gas safety appliance but also to accident investigating of explosion.

• International Journal of Naval Architecture and Ocean Engineering
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• v.9 no.2
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• pp.135-148
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• 2017

Topside areas on an offshore oil and gas platform are highly susceptible to explosion. A blast wall on these areas plays an important role in preventing explosion damage and must withstand the expected explosion loads. The uniformly distributed loading condition, predicted by Explosion Risk Analyses (ERAs), has been applied in most of the previous analysis methods. However, analysis methods related to load conditions are inaccurate because the blast overpressure around the wall tends to be of low-level in the open area and high-level in the enclosed area. The main objectives of this paper are to study the effects of applying different load applications and compare the dynamic responses of the blast wall. To do so, various kinds of blast pressures were measured by Computational Fluid Dynamics (CFD) simulations on the target area. Nonlinear finite element analyses of the blast wall under two types of identified dynamic loadings were also conducted.

• Journal of the Society of Naval Architects of Korea
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• v.57 no.4
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• pp.207-212
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• 2020

To decide a separation distance of the redundant vital equipment in a naval ship, the damage radius due to an aerial explosion should be estimated. In this research, a simplified formula for the damage radius has been developed by using existing empirical formulae for reflected shock pressure and shock lethality value of equipment. As a numerical example, the damage radius for a typical pump aboard a naval ship has been calculated by the developed formula and compared with the results calculated by Measure of Total Integrated Ship Survivability (MOTISS) which is one of survivability analysis codes verified, validated and accredited by the US Navy. Also, comparison with the results calculated by existing other simplified formulae has been made.

• Journal of the Korean Society for Marine Environment & Energy
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• v.10 no.4
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• pp.211-217
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• 2007

Due to advanced new weapons and changes in the combat environment, survivability improvement methods for naval ship design have continuously evolved. Surface naval ships are easily detected by the enemy and, moreover, there are many attack weapons that may be used against surface naval ships. Therefore, it is important for modem naval ships, especially combat naval ships, to ensure survivability. In order to design a naval ship considering survivability, the designers are required to establish reasonable attack scenarios. An explosion may induce local damage as well as global collapse of the ship. Therefore, possible damage conditions should be realistically estimated at the design stage. In this study, an ALE technique was used to simulate the explosion analysis, and the survival capability of damaged naval ships was investigated. Especially, the author have establish the simple method of estimation of survival time for damaged naval ships.

• Coupled systems mechanics
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• v.7 no.3
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• pp.333-351
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• 2018

In the present paper, the behavior of the Karaj double curvature arch dam is studied focusing on the effects of structural nonlinearity on the responses of the dam body when an underwater explosion occurred in the reservoir medium. The explosive sources are located at different distances from the dam and the effects of the cavitation and the initial shock wave of the explosion are considered. Different amount of TNT are considered. Two different linear and nonlinear behavior are assumed in the analysis and the dam body is assumed with and without contraction joints. Radial, tangential and vertical displacements of the dam crest are obtained. Moreover, maximum and minimum principal stress distributions are plotted. Based on the results, the dam body responses are sensitive to the insertion of joints and constitutive model considered for the dam body.

• Journal of the Korea Institute of Military Science and Technology
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• v.18 no.6
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• pp.822-828
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• 2015

This paper describes computer simulation program of high-altitude electromagnetic pulse (HEMP). The HEMP is produced by the gamma rays form high-altitude nuclear explosion. The gamma rays generate a current of compton electron that leads to the production of electromagnetic fields. In case of high altitude nuclear burst, the electrical fields at the earth's surface are strong enough to be damaged for electrical and electronic device over a very much larger area. Therefore, national infrastructure will be serious damage such as power grid and communication network. In this paper introduce simulation program for calculation of HEMP and present to simulation study results of high altitude nuclear explosion experiment from U.S. and U.S.S.R.

• Journal of Korean Association for Spatial Structures
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• v.15 no.1
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• pp.95-102
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• 2015

The purpose of this study is to establish and examine the analytical methods based on FEA to predict the behavior of the precast prestressed concrete panels under blast loading. The precast prestressed concrete structures are on the rise, but there is little research in this regard explosion. In this paper, we set the variable to the three models. TNT 500 kg was an explosion in the standoff-distance 3m. In conclusion, the precast models damage was concentrated in the bonded portion. The concrete panels after an explosion occurred continuously deformed. But the including prestressed panels deformation occurs only at the beginning of the explosion were able to see the results.

• Journal of the Korean Institute of Gas
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• v.10 no.4 s.33
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• pp.52-62
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• 2006

In this study, we tried to propose a selection method of release scenarios and a method of consequence analysis at a gas explosion by pipe release. Thus, release rates, damage areas of the facilities, and fatality areas were estimated and analyzed at various release conditions(temperature, pressure, release material, etc). As a results, we could conclude that the rupture was the worst case of release scenarios, and at release rates and damage areas were better estimated by the weighted average method considering a generic failure frequency of the release hole than by an arbitrary selection of the release hole.

• Journal of the Korean Institute of Gas
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• v.19 no.2
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• pp.12-19
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• 2015

$CO_2$ is non-flammable, non-toxic gas and not cause of chemical explosion. However, various impurities and some oxides can be included in the captured $CO_2$ inevitably. While the $CO_2$ gas was temporarily stored, the pressure in a storage tank would be reached above 100bar. Therefore, the tank could occur a physical explosion due to the corrosion of vessel or uncertainty. Evaluating the intensity of explosion can be calculated by the TNT equivalent method generally used. To describe the physical explosion, it is assumed that the capacity of a $CO_2$ temporary container is about 100 tons. In this work, physical explosion damage in a $CO_2$ storage tank is estimated by using the Hopkinson's scaling law and the injury effect of human body caused by the explosion is assessed by the probit model.