RESEARCH ON THE BEHAVIOR OF COMPOSITE FRAME WITH CFST COLUMNS AND COMPOSITE BEAM AFTER EXPOSURE TO FIRE

摘要

A 3-D finite element model (FEM) is developed herein to simulate the post-fire behavior of composite frames with CFST columns and steel beam with reinforced concrete slab. The finite element program ABAQUS was adopted for the analysis. Also accurate thermal and material model,element type and solution method were assumed. The FEM was verified valid by contrasting with some experimental results. Meanwhile,parametric analysis was performed to investigate the influence to the load to displacement relationships of CFST composite frames after exposure to fire. The strength of steel tubes,the concrete strength of columns,the steel ratio of columns,and the axial load ratio were considered as parameters. The result can improve the theory of CFST fire resistance.