http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Behavior of circular CFT columns subject to axial force and bending moment
곽지현,곽효경,김진국 국제구조공학회 2013 Steel and Composite Structures, An International J Vol.14 No.2
The major objective of this paper is to evaluate the behavior and ultimate resisting capacity of circular CFT columns. To consider the confinement effect, proper material models with respect to the confinement pressure are selected. A fiber section approach is adopted to simulate the nonlinear stress distribution along the section depth. Material nonlinearity due to the cracking of concrete and the yielding of the surrounding steel tube, as well as geometric nonlinearity due to the P-Δ effect, are taken into account. The validity of the proposed numerical analysis model is established by comparing the analytical predictions with the results from previous experimental studies about pure bending and eccentric axial loading. Numerical predictions using an unconfined material model were also compared to investigate the confinement effects on various loading combinations. The ultimate resisting capacities predicted by the proposed numerical model and the design guidelines in Eurocode 4 are compared to evaluate the existing design recommendation.
곽지현,김동석,구재현 한국화재소방학회 2013 한국화재소방학회논문지 Vol.27 No.5
An automatic spreading fire extinguisher usually installed in a closed area like a boiler room, a laundry store or a restaurant’s kitchen room is one of the fire protection equipments. This extinguisher automatically discharges dry powder,extinguishing fire. As this extinguisher has the extinguishing capability applicable to the nominal protection area, objects outside the area cannot be properly extinguished. However only its number is being requested according to the floor area in the related laws, and the extinguishing capability depends on the distance from a fire source. In this study we tried to investigate the extinguishing capability of the automatic spreading fire extinguisher in accordance with horizontal separation distance from a fire source. It appeared that the maximum horizontal separation distance was about 30 cm for both class A and B fire to be certainly extinguished. 보일러실이나 세탁소, 또는 음식점과 다중이용업소의 주방에 주로 설치하는 자동확산소화장치는 화재발생 시 화염이나열에 의해 자동으로 약제가 방출되어 화재를 진압하는 소화기구 중 하나이다. 이 소화장치는 공칭방호면적에 해당하는소화능력을 가지고 있으므로 방호대상물이 이 범위를 벗어나 있으면 유효한 화재진압이 보장되지 않지만 현행 기준에는바닥면적에 따른 설치갯수만 요구하고 있다. 따라서 방호대상물과의 이격거리에 따라 소화성능은 달라지게 되며 이에 대한 특성을 고찰하고자 천장높이가 2.5 m인 모형화재실에 본 소화장치를 설치하고 A급, B급 모형가연물과의 수평이격거리에 따른 소화실험을 실시하였다. 실험결과 일반가연물과 유류가연물을 모두 확실하게 소화할 수 있는 최대수평이격거리는 약 30 cm인 것으로 나타났다.