基于空腔辐射效应的钢索截面温度场分析

该文基于传热学基本理论及ABAQUS数值传热分析平台，以圆柱壁的截面径向导热热阻和空腔热阻代替平壁导热热阻，分别建立了四面受火工况下具有空腔几何特征的钢索截面升温理论及数值传热模型，得到考虑空腔辐射传热效应的无防火保护钢索截面升温历程，将其与具有等效截面圆钢的升温历程比较，研究表明:截面尺寸和空腔辐射效应对钢索截面升温历程有显著影响，空腔辐射效应在火灾升温初期加快了钢索截面的升温速率；最终在钢索热传导理论分析及数值模拟基础上，建议了钢索截面升温计算式，从而准确确定火灾升温历程中钢索材料性能衰减程度，正确评估预应力张拉结构中钢索的抗火承载力。

EFFECTS OF CAVITY RADIATION ON THE TEMPERATURE DISTRIBUTION IN STEEL CABLE SECTIONS

In this study, the thermal resistance of plates is represented by both the thermal resistance of cylinders in the radius direction and cavity to establish the cross section temperature theory and the numerical heat transfer models in steel cables without protection material exposed to fire by analytical method based on heat transfer theory and using ABAQUS software to simulate the heat transfer. It is compared with the cross section temperature field between steel cables and steel bars. It is indicated that the size of cable sections and the cavity radiation have strong effects on the temperature history of steel cables, and the cavity radiation speeds up the temperature in steel cables. It suggests that the cross section temperature calculation formula in steel cables based on the heat transfer theory and the numerical simulation can accurately determine the extents of deterioration of steel cable material properties during the fire heating process and accurately evaluate the fire resistance capacity of steel cables.