新型装配式混凝土框架节点抗火性能有限元分析

Finite Element Analysis of Fire Resistance of New Fabricated Concrete Frame Joints

为考察一种新型装配式混凝土框架节点的抗火性能,采用有限元分析软件ABAQUS进行模拟火灾分析,研究柱轴压比、梁荷载比、轴压偏心率、混凝土保护层厚度、节点连接螺栓直径对节点抗火性能影响。结果表明,所有分析节点耐火极限均能满足规范要求,且在火灾中均以梁变形过大失效;在接近耐火极限时,节点变形速度明显增大,破坏具有突然性;分析参数中,耐火极限随轴压比、荷载比、偏心率的增大而减小,随混凝土保护层厚度、螺栓直径增大而增大,其中轴压比、偏心率和混凝土保护层厚度的变化对耐火极限影响较大。

In order to investigate the fire resistance of a new type of prefabricated concrete frame joints,finite element analysis software ABAQUS is used to simulate the fire analysis.The column axial pressure ratio,beam load ratio,axial pressure eccentricity,concrete protective layer thickness and joint bolts are studied.Diameter affects the fire resistance of the joint.The results show that the fire endurance of all analytical joints can meet the requirements of the specification,and the deformation of the beam is too large;when the fire resistance is close to the fire resistance,the deformation speed of the joint obviously increases,and the damage is abrupt;in the analysis parameters,the fire resistance is limited with the axial pressure.The fire resistance decreases with the increase of axial compression ratio,load ratio and eccentricity,and increases with the increase of concrete cover thickness and bolt diameter.The changes of axial compression ratio,eccentricity and thickness of concrete cover have great influence on fire endurance.