Numerical Simulation Of Local Fire Rc Frame Beams

Reinforced concrete structure is one of the most widely used structure forms at present, and its mechanical behavior under fire has been widely concerned by researchers.Based on the key project in Hunan Province Science and Technology Plan of "Analysis and Simulation Study of the Whole Process on Response of Reinforced Concrete Frame Structure under Fire",the response of reinforced concrete members under fire research is taken in this thesis, and the analysis program about the response of members under fire are wrote at the same time.The main works are as follow:1. The existing Fire Resistance Design Methods for Reinforced Concrete structure are introduced and analyzed, and the advantages and disadvantages of each design method is discussed, And then proper design method is selected to analyze the response of Reinforced Concrete Member under fire.2. The variation laws about high-temperature mechanical properties of concrete and reinforcement at home and abroad were compared, in order to choosing the proper one to carry out the analysis of reinforced concrete members. The thermodynamic constitutive model of concrete and reinforcement has been established, considering some factors in the deformation of members, such as the strain-stress relation, free expansion, transient thermal strain and short-term creep under high temperature and so on.3. Reinforced Concrete Member is discretized using beam-column elements of equal section:after the member is segmented along the longitudinal direction and meshed in the sectional direction.As a result, the Reinforced Concrete Member is discretized into a great number of equal-section prism elements.On the basis of the constitutive relation, the relation between beam and column elements and the thermodynamic constitutive model,the general stiffness matrixes and balance equation were deduced in the thesis.4. Using the method of structural mechanics, the restraint of the fired components caused about the surrounding components was simplified into elastic constraints on the two ends of the component. The effect of restrictions was reflected by modifying the general stiffness matrix.With the introduction of the boundary conditions, the response of reinforced concrete member under fire was obtained by solving the balance equation through the Newton-Raphson method.In addition, the analysis program for the response of reinforced concrete members under fire was built with FORTRAN language...