Nonlinear Analysis on Reinforced Concrete Frame Joints under Thermal-Stress Coupling

Based on ABAQUS finite element analysis, nonlinear analysis about mechanical performance of reinforced concrete beam-column joints under thermal-stress coupling is carried out. This paper mainly research the temperature field distribution, the beam deformation of frame joints under fire and the influence of different parameters such as the axial compression ratio, beam layer thickness, reinforcement ratio on fire resistance of frame joint. Conclusions was drawn as: forming temperature gradient from the outside to the inside in frame joint; displacement of the end of the beam suddenly increase after plastic hinge appearing, the sudden destruction contains contingency; Due to the damage began from plastic hinge at the end of the beam, the axial compression ratio has less influence about fire resistance of frame joint; The thicker of beam layer thickness, the longer of joint refractory limit; the higher of reinforcement ratio,the later of plastic hinge's formation, that is good for fire resistance.