NUMERICAL ANALYTICAL METHOD OF REINFORCED CONCRETE SPECIALLY-SHAPED COLUMN SUBJECTED TO HIGH TEMPERATURE

Reinforced concrete specially-shaped column is divided into several segments along its height. The sectional curvature is supposed to vary linearly in each segment. Combining the conjugate beam method and the nonlinear incremental finite element analytical method of reinforced concrete section under force and temperature, a numerical analytical method for specially-shaped column subjected to high temperature is proposed. Moreover, a method for determining the position of the point in the stress and stress-strain curves of concrete and steel bar in every increment step under elevated temperature is suggested. A corresponding computer program RCSSCF is developed and the second-order effect of axial forces is considered in the program. The reliability of the program is validated using test results. Studies show that the fire resistance calculated using the numerical method based on the conjugate beam is slightly less than the results calculated using the numerical method based on deformation assumption on the whole.