中文摘要：

将钢筋的圆形截面等效为面积相等的方形截面,采用四边形单元建立配置钢筋、型钢的混凝土截面的二维温度场分析模型,分析纵筋配筋率、型钢含钢率对混凝土截面温度场分布的影响.算例计算结果表明：钢筋对截面温度场分布计算结果影响较小,钢筋的存在使保护层内混凝土的温度降低,核心混凝土的温度升高,忽略钢筋对截面温度场分布的影响是合理的.型钢对截面温度场分布的计算结果影响较大,受火180min内混凝土截面内型钢翼缘中心处和截面形心处温度计算结果最大分别相差17.1℃和98.7℃;高温下型钢混凝土构件的抗火性能研究中,需要考虑型钢对截面温度场分布的影响;型钢混凝土构件火灾灾后性能评定中,核心型钢的力学性能可基本恢复.

英文摘要：

The circular section of steel bar is equivalent to a square section with the same area,and the analytical model for two-dimensional temperature field of concrete section with steel bar or shaped steel was established using quadrangular element.Then the influence of the steel ratio of longitudinal reinforcement and shaped steel on the temperature field distribution was investigated.The results of numerical examples show that： the influence of reinforcement ratio on the temperature field distribution of concrete section is little and is neglectable.The temperature of cover concrete is decreased by reinforcement while that of core concrete is increased.The shaped steel ratio has great influence on the temperature field distribution of concrete section.When the fire exposure time is 112 min,the temperate differences at the center of flange and the centroid of cross section are 17.1 ℃ and 98.7 ℃,respectively.It is necessary to consider the influence of shaped steel on the temperature field distribution in the fire resistance analysis of steel reinforced concrete（SRC） members under elevated temperature.The mechanical behaviour of core shaped steel can mostly be recovered in the residual strength evaluation of SRC members.