外包钢加固钢筋混凝土梁的抗火性能研究

利用有限元软件ABAQUS,建立了在标准升温下外包钢加固钢筋混凝土梁的温度场和力学分析模型。获得了外包钢加固钢筋混凝土梁的抗火全过程曲线。采用抗力折减系数法分析了外包钢混凝土梁的承载力在火灾下的变化情况,同时分析了各参数对全过程曲线及抗力折减系数的影响。结果表明:加固梁在高温作用下,初始时刻出现反拱;初始时间增长时,反拱幅度增加,极限承载力降低;随着混凝土梁高和角钢厚度的增加,高温下梁的极限承载力增大,抗力折减系数降低缓慢。

Fire-resistant Behavior of Reinforced Concrete Beams Strengthened with External Steel Clad

By using the software ABAQUS,a finite element model was established to calculate the temperature field and the fire-resistant mechanical behavior of RC beams strengthened with external steel clad.Load-displacement curves changing with time of fire exposure were achieved under ISO 834 standard fire.The load capacity ratio was studied,and the related factors were also derived. Results showed that the reinforced beams have anti-arch at the initial moment under high temperature. As the initial time grows,the arch amplitude increases and the ultimate bearing capacity of the beams decreases. The main factors related to the full curve and fire resistance load ratio were the height of beams and the thickness of the angle. When the height of beams and the thickness of the angle increase.