Research On Seismic Behavior Of Specially Shaped Columns With Inserted Concrete Filled Steel Tubes

The mechanical properties of Specially shaped columns are inferior to those of ordinary rectangular columns.How to improve the seismic performance of specially shaped columns has important research significance.In view of the fact that steel tubes can bring significant constraining effects to confined concrete,the specially shaped concrete columns with inserted steel tubes can compensate for the structural defects of concrete crushing and steel tube buckling to a certain extent.The seismic performance of the inserted CFST specially shaped columns assembly is studied.Based on the CDP model in ABAQUS software,this paper carries out numerical simulations of the inserted CFST specially shaped columns composite components.The main work focuses on the following points:(1)Based on the current research results on concrete damage and plastic constitutive relations,summarize the plastic damage constitutive equation and the calculation method of related plastic deformation damage factor,and select the strength suitable for the whole process analysis of thin-walled steel tube concrete composite special-shaped columns.Guidelines and constitutive relations.(2)Choose the contact type suitable for simulating the squeeze-bond-slip behavior between steel pipe and concrete,select the appropriate boundary conditions and loading methods in combination with the actual project,and implement the grid layout and unit selection according to the characteristics of the components in this paper.(3)With the help of numerical simulation analysis method,according to the analysis results of the related literatures,it is verified that the numerical simulation results of this paper are in good agreement with the relevant experimental results.The numerical simulation can be used to analyze the stress process of this kind of specimens.The numerical simulation of thin-walled concrete-filled-steel-concrete-concrete-shaped special-shaped columns was carried out,and the hysteresis curves and skeleton curves were explored through numerical analysis results.(4)Orthogonal test method was used to study the influence degree and related laws of different factors on the mechanical properties of special-shaped CFST columns,and the obtained rules were applied to the design of components and structures.