接触热阻及热湿耦合作用对火灾下钢管混凝土柱温度场影响的研究

STUDY ON THE EFFECT OF THERMAL CONTACT RESISTANCE AND COUPLED HEAT AND MOISTURE ON TEMPERATURE FIELD OF CFST COLUMNS

  • 摘要: 为更好地分析火灾下钢管混凝土柱截面的温度场,建立了高温下核心混凝土的一维传热传质模型及钢管混凝土柱的传热模型,利用多物理场耦合分析软件COMSOL对核心混凝土的温度场进行了分析,而后研究了接触热阻对钢管混凝土柱截面温度场的影响。分析结果表明:考虑接触热阻和水蒸气等因素的影响后所计算的温度场能够更为真实地反映火灾下钢管混凝土柱截面温度发展的实际情况;与热传导计算模型相比,该文所述的混凝土传热传质数学模型能够更好地描述火灾下混凝土的温度场问题;不考虑接触热阻时计算的柱截面温度高于考虑接触热阻时的计算结果,且越靠近核心混凝土表面计算结果误差越大。

     

    Abstract: To predict the temperature field of concrete filled steel tubular (CFST) columns more accurately, the one-dimensional heat and mass transfer model of core concrete and the heat transfer model of CFST columns under fire conditions are established. The temperature field of core concrete is analyzed by using COMSOL, and then the effect of thermal contact resistance on the temperature field of CFST columns is investigated. The result indicates that: 1) considering thermal contact resistance and water vapor, the temperature developing inside CFST columns is predicted accurately; 2) compared with the heat conductive model, the heat and mass transfer model of concrete proposed in this paper generates more accurate prediction of the temperature field; 3) considering the thermal contact resistance, the calculated temperature of the columns is lower and the calculation error is larger near the surface of core concrete.

     

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