【摘要】 利用ANSYS软件对火灾发生时钢筋混凝土梁截面的最高温度分布进行了分析,确定了火灾后钢筋混凝土梁的抗力折减系数,建立了火灾后梁的抗力模型和极限状态方程。利用改进的一次二阶矩法计算了不同温度作用下钢筋混凝土梁在承受原设计荷载时的可靠性指标,分析了不同受火时间对钢筋混凝土梁可靠性指标的影响,为火灾后钢筋混凝土构件的破损评估分析提供了理论基础。算例分析表明,不同受火时间对钢筋混凝土梁的可靠性有很大的影响,梁在受火时间超过120分钟时,需进行加固维修。更多还原

【Abstract】 The ANSYS software was utilized to analyze the maximum temperature distribution of reinforcement concrete(RC) beam section during exposure to fire.Reduced coefficient of resistance of the RC beam after fire was decided,resistance model and limit state equation of the RC beam after fire was determined.Reliability index of RC beam after different fire duration was calculated through the AFORM method for the beam under original design load.Influence of different fire duration on reliability index of RC beam was analyzed and this paper supplies some theoretical basis to the damage assessment of the RC member.The results of specific calculated example indicate that different firs duration have impact on the reliability of the RC beam,and the beam should be strengthened when the fire duration is over 120 minutes.更多还原