Study On Axial Compression Double C Steel Concrete Composite Column

The prefabricated assembly structure is highly industrialized and conforms to the national strategy of energy saving and emission reduction.It has been strongly supported and popularized by the state,and many new assembly systems are constantly emerging.CS assembly structure belongs to one of them,and the main bearing role is double C steel concrete composite column.However,there is no provision for the bearing capacity of double C steel concrete composite columns.With the help of finite element analysis software ABAQUS,the numerical simulation of double C steel concrete composite columns is carried out in this paper.First,the nonlinear characteristics of the model,the mechanical properties of the material and the detailed establishment process are introduced.The correctness of the finite element model and its parameter selection is verified by comparing the numerical simulation with the experimental results.It provides a basis for the study of axial compression bearing capacity of composite columns by using ABAQUS.At the same time,the load displacement curve is studied and analyzed.It is found that the stress process of the combined long column can be divided into elastic stage,elastoplastic stage and plastic stage.Secondly,a large number of finite element models were established by finite element software ABAQUS.The four factors affecting the ultimate bearing capacity of composite columns were analyzed,including slenderness ratio,concrete strength,steel strength and thin-walled steel thickness.It is found that the ultimate bearing capacity of composite columns decreases with the increase of slenderness ratio,and increases with the increase of concrete strength and steel strength,and increases with the increase of the thickness of cold-formed thin-walled steel.The strength of steelhas little effect on the stiffness of the composite column,while the strength of the concrete,the thickness of the steel and the length and length have a greater influence on the stiffness of the composite column.With the increase of the slenderness ratio,the influence of the other three factors on the bearing capacity of the composite column gradually decreases.By drawing the slenderness ratio-stability coefficient curve,found only stability coefficient and slenderness ratio and steel strength,has nothing to do with the strength of concrete and steel thickness,the curve and the curve of Euler formula is similar,inspired by the stable use of concrete filled steel tube columns of the unified theory of number.Then,four kinds of concrete-filled concrete theory are introduced in detail: the unified theory of concrete-filled steel tube,the theory of superimposition,the theory of quasi concrete and the theory of quasi steel.Then we introduced the Chinese code GB50936-2014 compiled by the unified theory of CFST,the Japanese AIJ(1997)written by the superposition theory and the American AISC-LRFD(1994)prepared by the theory of quasi steel.By comparing the ultimate bearing capacity of composite short columns calculated by different standard formulas and simulation analysis,it is found that the results calculated by AISC-LRFD(1994)coincide well with those of finite element simulation.Therefore,it is recommended to use this standard formula to calculate the axial compression bearing capacity of composite short columns.Finally,using the unified theory of concrete filled steel tube and the marginal yield criterion,reference GB50936-2014 standard derivation process for long column stability coefficient,the double C type steel concrete composite paper bearing capacity of long columns axial compression,using MATLAB software to solve the equation,the columns bearing capacity calculation formula.Comparing the formula calculation with the simulated bearing capacity,it is found that the two are in good agreement,and the formula is close to 1 when calculating the short column stability coefficient,which proves that the formula has certain accuracy.