Analysis Of Circular Concrete-Filled Steel Tube Under Eccentric Loading

Though investigating the damages of buildings caused by earthquakes, people have noticed the design of columns plays a significant role in preventing the collapse of building in earthquakes. especially, with the increase of span and height of building, columns need to bear higher and higher axial load. Therefore, the columns are demanded to have high strength as well as high ductility. So the type of Concrete-Filled Steel Tube Columns has been presented. The main concept of CFT column is that steel tube and filled-in concrete of CFT column have the ability to bear axial load and can take the advantages of each material. Concrete-Filled Steel Tube Columns have become popular in structural elements used in buildings, arch bridges and Span structures due to their excellent performance characteristics including high compressive strength, good anti-seismic performance, low cost and convinient construction. Based on theoretical analysis and experiment date colleted, The key contents are summarized as follow:Research on the history and development of CFST is reviewed. Analysis of CFST under eccentric loading by scholars all over the world are summerized. The stress-strain relationship of the core concrete and steel of CFST members is introduced and main methods on ultimate bearing capacity of CFST members under eccentric loading are summarized.Based on the stress-strain relationship of the core concrete and steel tube, With basic mathematical knowledge, deformation compatibility conditions and equilibrium conditions, moment-cruvature curves and load-bearing capacity relationships of CFST members under eccentric loading is fitted by integral method. The effects of several main factors on these properties are also discussed.The paper validates the analytical models with various experimental results in literture to discuss the change of the bearing capacity with the influence of eccentricity in numerical analysis. The numerical analysis values are compared to the experimental results collected to verify the accuracy of considerition of eccentricity,Results are got by ANSYS with Constitutive relationship of core concrete consider of eccentricity. The paper compares the results with some experimental results in literture to verify the practicality of considerition of eccentricity.On the base of the existing equation established by Ding Faxing, formula used to predict the ultimate carrying capacity of CFST members under eccentric loading is improved by author. The results calculated from new formular are in strong agreement with the results of numerical calculation as well as experiment date collected.