Research On Seismic Behavior Of Box Steel Connected Prefabricated Concrete Columns

The joint structure of the prefabricated concrete column is the key of the whole prefabricated building system,which plays an important role in the safety and stability of the structure,and is also the core problem that affects the seismic performance of the structure and restricts the development of the prefabricated building.In order to keep the load transfer between the column component assembly,the node should have good strength,stiffness and stability,the seismic energy dissipation capacity,and ease of operation,based on the realization of prefabricated construction thought of pure dry connections,this paper proposes a "box steel connection of prefabricated concrete column" new type of prefabricated concrete column form.Through conceptualization design and theoretical calculation analysis of box shaped steel joints,the proposed design parameters of common assembly concrete column shaped steel joints in engineering are given.Through box steel connection assembly concrete column quasi static test,studies the component under axial pressure ratio level of mechanical performance and energy dissipation capacity,using ABAQUS software to set up and test components and the corresponding finite element model,by adding boundary conditions and applying the same as the experimental conditions of reciprocating load condition,the simulation analysis and calculation results compared with experiment results,the computer simulation results and experimental results is obtained by data than in a reasonable range of error,the finite element simulation analysis has certain reliability and accuracy.Two box shaped steel connected concrete assembly columns and one whole cast column were designed and fabricated.The low cycle reciprocating load tests were carried out under different axial pressure levels respectively.The seismic performance and energy dissipation capacity of this kind of assembled concrete column were studied from the aspects of hysteresis curve,skeleton curve,stiffness degradation,energy dissipation capacity and ductility.The test results show that the prefabricated concrete columns with box shaped steel joints have better mechanical performance and energy dissipation capacity,and the existence of section steel joints can maintain the synergistic effect of upper and lower columns,and have better integrity and stability.Using the finite element software ABAQUS,the component model of the prefabricated concrete column connected by box shaped steel was established and analyzed.The material properties,component connection mode,boundary conditions and loading system of the model were identical with the actual test conditions,and the failure mode,strain distribution and hysteresis curve of the prefabricated concrete column and joint domain were obtained.The accuracy of the simulation results was verified by comparative analysis with the test results,and the different parameters of the box joints were analyzed to explore the influence of different parameters on the stress condition of the joints.The method of pure dry connection of box shaped steel joint proposed in this paper is excellent,which improves the construction efficiency on site,can better protect the environment,and can effectively solve the problems of complex joints and unreliable connections in assembled building connection,so it has high practical application value.