受火作用下钢管混凝土柱非线性接触热阻理论分析

THEORETICAL ANALYSIS OF THE NONLINEAR THERMAL CONTACT RESISTANCE OF CONCRETE FILLED STEEL TUBE COLUMN UNDER FIRE CONDITION

目前现有的受高温火作用下钢管混凝土柱温度场的分析方法中,大多数学者考虑了界面处接触热阻的影响,但鲜有考虑接触热阻的非线性变化,这将对钢管混凝土柱温度场的精确分析产生一定程度的影响。从高温下钢管混凝土柱传热机理出发,考虑了初始间隙、界面温度、以及钢管与混凝土黑度等多种因素的影响,建立了接触热阻非线性模型。结合实际试验工况验证了理论的合理可行性,为精确分析高温下钢管混凝土柱的温度场提供了新的方法。

Among the existed methods to predict temperature field of concrete filled steel tube column under fire condition,the most scholars considered the effect of thermal contact resistance at the steel-concrete interface,but few considered the nonlinear changes of the thermal contact resistance,it would have a great influence on the accurate analysis of temperature field. The paper embarked from the heat transfer mechanism of concrete filled steel tube column under fire condition,considering many factors such as the initial gap,interface temperature and,the emissivity of the steel and concrete,the nonlinear model of the thermal contact resistance was established. Verifying the feasibility theory of reasonable combined with the actual conditions,the work provided a new method for the further accurate analysis of the temperature field of concrete filled steel tube column under fire condition.