Nonlinear Simulation And Analysis Of Self-Centering RC Column Base

Traditional reinforced concrete frame systems mainly rely on plastic deformation of main structural members such as beam and column to dissipate earthquake energy, and structure will have a relatively large plastic deformation after earthquake, which makes it difficult for structural repair or even leads to demolition and reconstruction of structure, and thus causes huge economic losses. The proposal of new structure system, with self-centering ability, provides a new solution to reduce residual deformation of structure and quickly recovery of structure functions.This thesis detailedly analysis mechanics of self-centering column base, and this member cannot only reduce residual deformation of structure, but also give a solution to instead of plastic deformation to dissipate seismic energy. Based on this, nonlinear simulation and analysis model of self-centering column constructed by OpenSees, analysis mechanical characteristics?failure modes?energy dissipation capacity and self-centering capacity of the column base.Under monotonic load, results of experiment and theoretical analysis, in good agreement with simulation values, which proves the effectiveness of nonlinear analytical model and the feasibility of theoretical analysis;when the axial compression ratio is greater, self-centering column base without energy dissipation devices at the rang of sectional height of column base into the serious nonlinear behavior, produce different degrees of residual deformation;when the axial compression ratio or the area of energy dissipation devices is too much, self-centering column base with energy dissipation devices lost the ability of reset due to the end section of energy dissipation devices achieved the maximum bending moment. Between the disability to reset of RC column and RC column, such as the ultimate bearing capacity?deformation capacity energy dissipation performance, are roughly equal.Meanwhile, parameter analysis of self-centering column base is carried out in the thesis, and the parameters involved include area of strand, initial stress of strand, the location of strand, and the features of energy dissipation devices such as its area, length and yield strength. The results list as follows:1) with increase of strands' area or far away from the center position, the moment resisting capacity of self-centering column base is improved; 2) When the lateral stiffness ratio is less than 0.35, increasing of the yield strength of energy dissipation devices or decreasing its area, is little influence for the ability of reset; 3) In order to prevent damage due to the local compression at the bottom of the column at the rang of sectional height, the paper demand intensified efforts for self-centering column base; in order to prevent brittle failure of concrete crushed at the dangerous section, the paper proposal intensified efforts at the location of stiffness mutation for self-centering column base with energy dissipation devices; 4) The design method of self-centering column base, provides the propose ideas under different seismic performance objectives.