• 대한금속재료학회지
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• 제49권9호
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• pp.671-677
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• 2011

Steel columns used in steel buildings are inclined to lose their strength when exposed to severe fire conditions, so fire resistance is required in most countries to protect against loss of life and building collapses. In Korea, the fire resistance of columns can be obtained by the fire test defined in KS F 2257-1, 7. The fire resistance of a steel column should be evaluated in terms of the column's conditions, such as various section types (H-section, hollow-section), the column's length and boundary conditions, and whether it is fixed or hinged. However, fire testing of steel columns is usually conducted on one standard-sized H-section over 3,000 mm, and the result is used as the column's fire resistance. This is not a reasonable way to ensure that a building can withstand fire conditions. In this study, to evaluate the possibility of calculating the fire resistance of steel columns with material properties of high tensile strength of SS 400, both load-bearing fire tests and calculation of steel temperatures were carried out. The results of temperature calculation were very similar to those obtained by fire test.

• 한국화재소방학회논문지
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• 제23권4호
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• pp.40-49
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• 2009

철도차량 내장재를 설치한 화재 시험 공간(ISO 9705)에서 대규모 화재시험이 수행되었다. 여기서 사용된 내장재는 2004년 12월에 공포된 철도차량에 대한 안전기준을 만족하는 내장재이다. 화원으로는 가스버너를 이용하였으며 가스버너의 출력은 시간에 따라 증가하도록 설정하였다. 본 시험의 목적은 철도차량 내장재의 화염전파와 발화에 대한 화재 성능 평가이며, 플레시오버로 성장하는 철도차량 내장재를 포함하는 화재에 대한 여러 데이터들의 확보이다. 이 데이터들은 철도차량 내장재의 화재 성장을 예측하는 모델을 검증하고 개발하는데 사용될 것이다.

• 한국안전학회지
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• 제23권6호
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• pp.76-83
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• 2008

In the course of increasing in human and material damage caused by fire, it is an important research field to develop clean extinguishing agent which does no harm to global environment as well as has a good extinguishing efficiency. This research is a basic step to develop a new clean extinguishing agent. In order to get a satisfactory result, we tested fire extinguishing ability using nitrogen and Novec mixtures gas which are inert gas and new clean extinguishing agent. We used Cup Burner Test made by international standard ISO-14520 regulations of gaseous extinguishing agent ability test, and the fuels used in the test are n-heptane, methanol, ethanol, iso-propanol and 1-butanol. The experimental results of flame extinguishing concentration are n-heptane 6.54%, methanol 8.47%, ethanol 6.98%, isopropanol 6.10% and butanol 6.54% by pure Novec agent. So the finding is that a new clean agent, Novec has an efficient extinguishing ability in a state of gas. Also, in a test as to mixtures gas of nitrogen and Novec, it has a good result for minimum oxygen concentration is under 16%.

• Computers and Concrete
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• 제12권5호
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• pp.717-737
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• 2013

In this study, experiment and numerical analysis were conducted to identify the heat transfer characteristics and behavior of high-strength concrete upon a fire. The numerical analysis was employed to forecast the characteristics and properties of the high-strength concrete upon a fire, which can not be accomplished through a fire test due to the specific conditions and restrictions associated with the test. The result of the numerical analysis was compared with that of the test to verify the reliability of the analysis. In the numerical analysis of the heat transfer characteristics and behavior of 80 and 100 MPa high-strength concrete upon a fire, the commercial software of ABAQUS(V.6.8) was used. It was observed from the experiment that the contraction of the concrete with fiber-cocktail was mitigated by 25~55 % compared with that without fiber-cocktail because the fiber controlled the heat transfer of the concrete and thus improved the fire-resistance performance of the column.

• 한국화재소방학회논문지
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• 제28권5호
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• pp.64-70
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• 2014

신경망은 연기입자의 광학적 특징으로부터 화원을 분석할 수 있는 유용한 도구가 될 수 있다. UL268에서 연기감지기 시험에 사용되는 세 가지 화원(종이화원, 목재화원, 인화성 액체화원)들의 광학적 특징으로 신경망을 훈련시켰다. 또한, 소광과 산란을 동시에 측정할 수 있는 연기챔버를 제작하여 연기의 광학적 특징을 얻고 그 결과를 신경망에 입력하였다. 종이화원, 목재화원, 인화성 액체화원을 대상으로 한 실험에서 신경망은 화원을 정확하게 구별하였다. 또한, 종이-목재화원, 종이-인화성 액체화원, 목재-인화성 액체화원과 같은 복합화원을 대상으로 한 실험에서도 화원을 모두 구별하였다.

• 한국신뢰성학회지:신뢰성응용연구
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• 제16권1호
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• pp.7-14
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• 2016

Purpose: The purpose of this study is to development the fire evaluating test methods for the Electric hair dryers. Methods: We was designed FMEA (Failure mode and effects analysis) in order to analyze the fire mechanism on the electric hair dryers and designed evaluating test methods (Durability tests on the environment, Mechanical durability tests) obtained through the two-step QFD (Quality Function Depolyment) and tested. Conclusion: We verified the evaluating fire test methods on the electric hair dryers through the analysis of the test results and some reproduction test.

• Steel and Composite Structures
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• 제38권1호
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• pp.87-102
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• 2021

To investigate the failure form, bending stiffness, and residual bearing capacity of monolithic composite beams with laminated slab throughout the fire process, fire tests of four monolithic composite beams with laminated slab were performed under constant load and temperature increase. Different factors such as post-pouring layer thickness, lap length of the prefabricated bottom slab, and stud spacing were considered in the fire test. The test results demonstrate that, under the same fire time and external load, the post-pouring layer thickness and stud spacing are important parameters that affect the fire resistance of monolithic composite beams with laminated slab. Similarly, the post-pouring layer thickness and stud spacing are the predominant factors affecting the bending stiffness of monolithic composite beams with laminated slab after fire exposure. The failure forms of monolithic composite beams with laminated slab after the fire are approximately the same as those at room temperature. In both cases, the beams underwent bending failure. However, after exposure to the high-temperature fire, cracks appeared earlier in the monolithic composite beams with laminated slab, and both the residual bearing capacity and bending stiffness were reduced by varying degrees. In this test, the bending bearing capacity and ductility of monolithic composite beams with laminated slab after fire exposure were reduced by 23.3% and 55.4%, respectively, compared with those tested at room temperature. Calculation methods for the residual bearing capacity and bending stiffness of monolithic composite beams with laminated slab in and after the fire are proposed, which demonstrated good accuracy.

• 한국화재소방학회논문지
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• 제30권4호
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• pp.1-5
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• 2016

본 논문은 영상화재감지기(Video Fire Detector)의 시험 및 설치기준에 관한 연구로서 FM Approvals, UL, ISO7240 및 NFPA 72 기준들을 서로 비교분석하여 국가화재안전기준 203 (NFSC 203)에 반영되어야 할 기준들을 제안하였다. 영상화재감지기의 시험과 관계된 FM Approvals 기준에는 연기형, 불꽃형으로 분류되고 비화재보시험이 있었으나 UL 기준에는 연기형만 제시되어 있었다. 외국 기준인 ISO 7240에서는 화재현상 검출유형 등 6가지를, NFPA 72에서는 화재현상 검출유형 등 3가지를 조사하였다. CCTV 설치 표준공법에서는 영상화재감지기의 설치기준에 필요한 항목이 15가지가 있었으며 설치방법에 따라 각 분야별 기준이 제시되어 있었다. 영상화재감지기 적용을 위해서는 감지기 시험항목 중 용어의 정의, 감지기의 구분, 구조 및 기능에 관련항목을 삽입하고 감도조정, 비화재보방지, 주위온도시험, 유효감지거리 및 감도와 시야각, 노화시험, 살수시험, 내화시험의 7개 항목의 적용이 필요하다. 현장 설치를 위해서는 국가화재안전기준 203 (NFSC 203)에 작동환경 및 조도기준을 설정하고 음향장치, 표시등의 설치거리 등의 기준을 삽입하여야 한다.

• Nuclear Engineering and Technology
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• 제54권5호
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• pp.1652-1656
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• 2022

Fire tests were conducted on cables using fire-retardant paint employed in nuclear power plants that transmit electrical power, control and instrument signals. The failure criteria of various power and control cables coated with fire retardant coating at three different coating thicknesses (~0.5 mm, 1.0 mm & 1.5 mm) were studied under direct flame test using Container Fire Test Facility (CFTF) based on standard tests for bare cables. A direct flame fire test was conducted for 10 min with an LPG ribbon burner rated at ten by fixing the cable samples in a vertical cable track. Inner sheath temperature was measured until ambient conditions were achieved by natural convection. The cables are visually evaluated for damage and the mass loss percentage. Cable functionality is ascertained by checking for electrical continuity for each sample. The thickness of cable coating on fire exposure is also studied by comparing the transient variation of inner sheath temperature along the Cable length. This study also evaluated the adequacy of fire-retardant coating on cables used for safety-critical equipment in nuclear power plants.

• Steel and Composite Structures
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• 제33권1호
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• pp.111-122
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• 2019

This paper presents an experimental work on the post-fire behavior of two kinds of innovative composite stub columns under eccentric compression. The partially precast steel reinforced concrete (PPSRC) column is composed of a precast outer-part cast using steel fiber reinforced reactive powder concrete (RPC) and a cast-in-place inner-part cast using conventional concrete. Based on the PPSRC column, the hollow precast steel reinforced concrete (HPSRC) column has a hollow column core. With the aim to investigate the post-fire performance of these composite columns, six stub column specimens, including three HPSRC stub columns and three PPSRC stub columns, were exposed to the ISO834 standard fire. Then, the cooling specimens and a control specimen unexposed to fire were eccentrically loaded to explore the residual capacity. The test parameters include the section shape, concrete strength of inner-part, eccentricity ratio and heating time. The test results indicated that the precast RPC shell could effectively confine the steel shape and longitudinal reinforcements after fire, and the PPSRC stub columns experienced lower core temperature in fire and exhibited higher post-fire residual strength as compared with the HPSRC stub columns due to the insulating effect of core concrete. The residual capacity increased with the increasing of inner concrete strength and with the decreasing of heating time and load eccentricity. Based on the test results, a FEA model was established to simulate the temperature field of test specimens, and the predicted results agreed well with the test results.