Nonlinear Analysis of Reinforced Concrete Frame Subjected to Fire

Reinforced concrete frames are one of most popular structures used in the world, but the research on their fire is at primary stage. In this thesis, the non-liner analysis of reinforced concrete frames at elevated temperature was analyzed by ANSYS, which included calculations and analysis of temperature field, structural deformation, and post-fire ultimate loadings, it was investigated in this paper with ANSYS. The analysis results indicate that the reinforced concrete frame members undergo internal force redistribution under a fire, and the super position of constraint internal forces with external loads causes destroy in beams and columns. Finally, the fire-resistance design of concrete structures was also discussed. In this thesis, by IS0834 Standard temperature-time curve. At the same time, the temperature field, the deformation law at high temperatures are also put forward. The temperature field is simulated using ANSYS, and the calculated results agree with test results. In a one compartment fire, obvious deformation of structural occurs lead to internal forces changed during fire, and the thermal expansion of the heated beams and columns is the main agitator in a one compartment fire. The degree of redistribution of the moment of the end of column is larger than the end of beam. Fire location has more influences on the fire resistance of reinforced concrete frame because the part of the structure at ambient temperature exerts different restrictions on the heated part. In the end, several suggestions are presented on the applicable design method of reinforced concrete frame in the fire.