Prediction of Heating Conditions and Thermal Response of Structural Members Exposed to Localized Flies

通过实验和数值研究，得到了以下结果：(1)火源局部化对柱体防火安全的有效性论证通过局部火源暴露钢柱的模型试验，发现其最高温升可降至均匀火焰加热柱旁的50 - 90%。采用钢结构和多孔丙烷燃烧器进行的模型实验表明，梁/柱的热流密度分布仅依赖于各自结构和结构/火焰结构。实验相关性已通过一系列全尺寸热通量测量得到验证。将数值流体力学应用于火源上方钢梁热流场的再现，通过改进火焰辐射的模拟，使再现误差在30%以内。(3)局部加热作用下金属结构温度响应的数值计算将有限差分法应用于局部火灾作用下钢柱温度场的预测。经验常数，如传热系数，已根据参考试验进行了调整。计算结果很好地再现了实验结果。

Through experiments and numerical studies, following results have been obtained.(1)Demonstration of the effectiveness of the localizedness of fire exposure for the fire safety of columnsThrough model experiments on a steel column exposed to a localized fire source, it has been found that its maximum temperature rise be reduced to 50 - 90 % of the column adjacent to an even flame heating.(2)Modeling and tabulation of heat flux distribution along a beam and a column exposed to a localized heatingModel experiments using steel structures and porous propane burners have yielded sole dependence of heat flux distribution along a beam/ column for respective configurations and structure/fire configurations. The experimental correlations have been validated against a series of full-scale heat flux measurements. Numerical fluid dynamcs has been applied to the reproduction of the heat flux field of the steelbeam above a fire source, which has resulted in th e reproduction within the error of 30 % by the improvement of the modeling of flame radiation.(3)Numerical cabulation of temperature response of metal structure exposed to a localized heatingFinite difference method has been applied to the prediction of the temperature field of a steel column exposed to a localized fire. Empirical constants such as heat transfer coeffifent have been tuned against a reference test. The cabulation has resulted in a fine reproduction of the experimental results.