Analysis Of Seismic Performance Of Circular Reinforced Concrete Columns With High-strength Spiral Stirrups

The demand of various types of buildings is increasing,and the development of civil engineering structures is also moving in the direction of large spans,higher towers,heavier loads,and worse environments.The widespread use of high-strength materials in concrete structures has become an inevitable trend.The high-strength concrete circular columns equipped with high-strength spiral stirrups are fully utilized by high strength spiral stirrup to restrain the high-strength concrete,which improve the ductility of the components,and have good seismic performance.On the other hand,numerical simulation with Finite Element Method is becoming an important tool for structural engineering analysis.In this thesis,the seismic performances of high-strength concrete columns with high-strength spiral stirrups by are studied with finite element software ABAQUS.The main contents of this research are as follows:(1)In order to ensure the accuracy of the finite element simulation,some hysteretic constitutive relations of high-strength concrete and high-strength spiral stirrups are compared and analyzed.Guo-Zhang model is selected for the concrete,and the damage factor of the concrete is also taken into account.For the steel bar,the Bilinear kinematic model considering the Bauschinger effect is selected.(2)By using the finite element software ABAQUS,twelve high-strength concrete circular column models with high-strength stirrups are established.Simulation and analysis of their seismic performance under low cyclic loading are performed.The main parameters are the axial compression ratio,the spacing of the stirrup,the reinforcement ratio of the longitudinal reinforcement,the strength grade of concrete,the setting of the stirrup and the diameter of the stirrup.(3)After the extraction and treatment of the results of the finite element calculation,the hysteresis curve and the skeleton curve of the specimens of each column are obtained.The main factors affecting the characteristics of hysteresis curves are analyzed.The skeleton curves of the specimens under different parameters are compared based on solving the bearing capacity and the displacement ductility of the specimens.(4)The influences of the parameters on strength degradation,stiffness degradation and total hysteretic energy consumption of each column specimen are further studied for the understanding of the comprehensive seismic capacity of the specimen columns.(5)According to the geometric parameters and material parameters from existing literature,a corresponding finite element verification model is established.The accuracy and rationality of the model is verified by comparing the simulation results with the experimental results.