• Journal of Korean Society of Steel Construction
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• v.28 no.1
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• pp.23-34
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• 2016

Concrete filled steel tube system has two major advantages. First, the confinement effect of steel tube improves the compressive strength of concrete. Second, the load capacity and deformation capacity of members are improved because concrete restrains local buckling of steel tube. It does, however, involve workability problem of using stud bolts or anchor bolts to provide composite effect for larger cross-sections. While the ribs inside the columns are desirable in terms of compressive behavior, they cause the deterioration in load capacity upon in-plane deformation resulting from thermal deformation. Since the ribs are directly connected with the concrete, the deformation of the ribs accelerates concrete cracking. Thus, it is required to improve the toughness of the concrete to resist the deformation of the ribs. Welding built-up tubular square columns can secure safety in terms of fire resistance if the problem are solved. This study focuses on mixing steel fiber in the concrete to improve the ductility and toughness of the columns. In order to evaluate fire resistance performance, loaded heating test was conducted with 8 specimens. The behavior and thermal deformation capacity of the specimens were analyzed for major variables including load ratio. The reliability of heat transfer and thermal stress analysis model was verified through the comparison of the results between the test and previous study.

• Journal of the military operations research society of Korea
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• v.29 no.2
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• pp.1-12
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• 2003

Knowing the characteristic of battle duration is important for commanders and logicians in the analysis of combat realization. Analytic solutions for mean and standard deviation can be found in small sized battles. Stochastic combat simulation model is utilized to study a probabilistic behavior of the combat duration. Output data is fitted to a certain probability distribution and some moments such as skewness and kurtosis are investigated. Fire allocation strategies, reselect options, interfiring time random variables, and kill rates are considered to investigate how they affect the battle termination time.

• Magazine of the Korea Concrete Institute
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• v.14 no.2
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• pp.24-29
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• 2002

산업화에 따른 인구 집중현상의 결과 도심지의 밀집형 고층주거형 구조물에 발생할 수 있는 화재는 인명과 경제적인 손실을 가져올 수 있으므로 이에 대한 체계적인 방재 시스템을 요구한다. 구조공학적인 측면에서 내화 특성은 화재에 대한 최후의 방어선으로서 구조적인 안정성을 유지하여야 한다. 화재로 인한 구조부재의 파괴는 구조체의 강성 및 강도저하가 주요 원인으로 근처 다른 구조부재의 파괴로 발전하면서 종국적으로 전체 구조물이 붕괴할 수도 있다.(중략)

• Proceedings of the KSR Conference
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• 2008.06a
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• pp.1768-1772
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• 2008

The authors previously presented that the experimental technique using fine bubbles generated by electrolysis simulated fire behavior in a tunnel. We improve this experimental setup to enable this to be considered tunnel-ventilation by circulation of salt water. In this paper we introduce the new experimental setup and the visualization of fine hydrogen bubbles simulated smoke in a ventilated tunnel by using a laser sheet are presented.

• Journal of information and communication convergence engineering
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• v.2 no.3
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• pp.172-176
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• 2004

In special effects industry there is a high demand to convincingly mimic the appearance and behavior of natural phenomena such as smoke, waterfall, rain, and fire. Particle systems are methods adequate for modeling fuzzy objects of natural phenomena. This paper presents particle system graphics library for generating special effects in video games and virtual reality applications. The library is a set of functions that allow c++ programs to simulate the dynamics of particles for special effects in interactive and non-interactive graphics applications, not for scientific simulation.

• Journal of the Korean Ceramic Society
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• v.17 no.4
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• pp.188-196
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• 1980

To investigate the corrosion behavior of the clay-bonded kaolin chamotte by molten aluminum, the mixture of 20 wt% fire clay and 80 wt% kaolin chamotte was prepared and fired in the temperature range 900~120$0^{\circ}C$. The specimens fired at each temperature were reacted with molten aluminum at 90$0^{\circ}C$. The results obtained in this experiment are as followed. 1) It was confirmed through X-ray diffraction analysis that the clay-bonded kaolin chamotte exposed to molten aluminum suffered penetration by the reaction of aluminum with silica forming alumina and metallic silicon. 2) Penetration was independent whether the silica existed as free or one component of mullite. 3) Penetration of the specimen fired at 90$0^{\circ}C$ was negligible while the others fired above 100$0^{\circ}C$ showed remarkable penetration. 4) Penetration rate at 90$0^{\circ}C$ was parabolically increased with the holding time as in the case of metal oxidation.

• Proceedings of the Korea Concrete Institute Conference
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• 2005.05a
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• pp.127-130
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• 2005

The purpose of this study is to investigate the flexural behavior of reinforced concrete beam members exposed to high temperature. In order to study the flexural behaviors, the 17 specimens have been tested with variables of reinforcement ratios($0.5\rho_{max},\rho_{min}$), heating conditions(nonheating, 400$^{circ}C$, 600$^{circ}C$, 800$^{circ}C$ heating and 1 hour preservation) and loading state(stressed and residual state). The results show that the stiffness and strength of specimens are lower when they are exposed to higher temperature and the pattern of crack and color of specimens exposed to fire are different from ordinary concrete members.

• Proceedings of the Korea Concrete Institute Conference
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• 2004.11a
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• pp.585-590
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• 2004

An analytical method is proposed for the analysis of the reinforced concrete flexural beam subjected to high temperature. The analysis procedure for the material properties, in this study, is subdivided into two types; thermal properties for temperature distribution analysis and mechanical properties for structural analysis. Using F.D.M. and segmentation method, the program was made to predict the thermal behavior of RC beams during heating. In previous studies, the structural behavior of fire damaged RC beams was investigated though experiments. Comparing the result by program to the one by experiment, the comparison indicated that the proposed segmentation method for the thermal respose analysis present fairly a good agreement with experiment.

• Fire Science and Engineering
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• v.31 no.2
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• pp.1-8
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• 2017

A sandwich panel is a composite material composed of a double-sided noncombustible material and insulation core which is used in the inner, outer walls, and roof structure of a building. Despite its excellent insulation performance, light weight and excellent constructability, a flame is brought into the inside of the panel through the joint between the panels, melting the core easily and causing casualties and property damage due to the rapid spread of flame. The current Building Law provides that the combustion performance of finishing materials for buildings should be determined using a fire test on a small amount of specimen and only a product that passes the stipulated performance standard should be used. This law also provides that in the case of finishing materials used for the outer walls of buildings, only materials that secured noncombustible or quasi-noncombustible performance should be used or flame spread prevention (FSP) should be installed. The purpose of this study was to confirm the difference between the dangers of horizontal and vertical fire spread by applying FSP, which is applied to finishing materials used for the outer walls of buildings limitedly to a sandwich panel building. Therefore, the combustion behavior and effects on the sandwich panel according to the application of FSP were measured through the construction to block the spread of flame between the panels using a full scale fire according to the test method specified in ISO 13784-1 and a metallic structure. The construction of FSP on the joint between the panels delayed the spread of flame inside the panels and the flash over time was also delayed, indicating that it could become an important factor for securing the fire safety of a building constructed using complex materials.

• Journal of Korean Tunnelling and Underground Space Association
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• v.21 no.1
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• pp.189-199
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• 2019

In this study, behaviors of fire smoke in the operation of disaster prevention facilities (smoke damper, jet fan) in a tunnel-type structure (soundproof tunnel) were investigated numerically and results of the investigation were compared and analyzed. Through the simulation and analysis, it was found that there was a significant change in the patterns of fire smoke between the opening of the ceiling of a fire vehicle and the closing, and it was shown that the critical temperatures of PC and PMMA, main materials of a soundproof tunnel were not exceeded. In addition, the simulation of installation intervals of smoke dampers showed that the maximum temperature of a soundproof tunnel without smoke dampers was $552^{\circ}C$ while it reached $405^{\circ}C$ when smoke dampers were installed at the installation interval of 50 m. The simulation of the operation of a jet fan showed that the maximum temperature of a soundproof tunnel without a jet fan was $549^{\circ}C$ while it reached only $86^{\circ}C$ when a jet fan was operating. Therefore, it is highly expected that they could create a favorable environment for evacuation and protection of soundproofing materials, and it would be necessary to promote basic studies on tunnels serving various functions and purposes.