Nonlinear Analysis Of Seismic Behavior Of Frame Columns Based On OpenSEES

The sufficient seismic bearing capacity and ductility of frame column is the key to prevent the building collapse in the earthquake. Therefore, it is of great significance to study the mechanical behavior of frame columns under cyclic loading.However, the simple experiments will consume a lot of power, material resources, the numerical simulation methods can be more fully reflect the mechanical properties of the frame structure, and provide sufficient basis for testing and engineering applications. Based on the finite element OpenSEES, the following aspects are carried out in this paper:(1) Based on OpenSEES, the nonlinear analysis of the seismic test of RC columns is carried out and compared with the experimental results: The fiber model of reinforced concrete columns can be used to simulate the hysteretic behavior of RC columns by using the constitutive relations of concrete02, steel02 and saatcioglu, and the calculated results are in good agreement with the experimental results. When using OpenSEES to take the numerical simulation, the influence of the P-Δ effect on the stiffness degradation of the late loading should be considered, and the number of points in the calculation should be taken as 3.(2) Based on OpenSEES, The numerical simulation of steel fiber reinforced ultra high strength concrete short column and PVA fiber super high strength concrete short column are carried out and compared with the experimental results: the error values of the recovery force curve, the displacement ductility coefficient, and the equivalent viscous damping coefficient by numerical simulation are all in a small range, and the OpenSEES can be used to simulate the nonlinear analysis of the seismic test of fiber reinforced concrete structure. The incorporation of steel fiber and PVA fiber can improve the ductility of the common column, so that the displacement ductility coefficient and the ultimate displacement angle can meet the seismic demands, and with the increase of fiber content, the plastic deformation and energy dissipation capacity of the corresponding increase.(3) Based on OpenSEES, the numerical simulation of UHTCC reinforced frame column is carried out to study the hysteretic behavior, ductility and energy dissipation capacity, find that the ductility and energy dissipation capacity of UHTCC reinforced frame columns are obviously increased, which can make the Shear brittle failure turn to the plastic failure mode. On this basis, the simulation value and the theoretical value are compared to verify the rationality of OpenSEES to simulate the seismic performance of UHTCC material.Then, discuss the factors of characteristic value of hoop, reinforcement ratio, axial compression ratio,which can have effect on seismic behavior of UHTCC reinforced frame column, and consider the limit value of axial compression ratio of UHTCC column is 0.8.When using UHTCC in plastic hinge region can reduce the amount of confinement reinforcement and shear reinforcement.