Whole Life Cycle Of Concrete Filled Steel Tubular Column Mechanical Properties Research

In this paper,the finite element software ABAQUS is used to analyze and study the mechanical properties of whole life cycle of the concrete filled steel tube columns subjected to axial load and eccentrical load,including the following three aspects:(1)The model is verified by the calculation of the initial stress of the steel tube,initial concrete imperfection and the long-term loads respectively.The calculated results are in good agreement with the test results.Based on this,the analysis model of the whole life cycle mechancial properties of the CFST columns subjected to axial load is established,the whole process of loading behavior and working mechanism are analyzed in detail.Finally,the bearing capacity parametric studies are conducted in terms of the initial stress coefficient ?,ratio of concrete gap ? and the long-term load ratio n.The results show that the ratio of concrete gap has a certain effect on the bearing capacity,the initial stress coefficient and the long-term load ratio have less influence on the bearing capacity.(2)The model is verified by the calculation of the initial stress of the steel tube,initial concrete imperfection and the long-term loads respectively.The calculated results are in good agreement with the test results.Based on this,the analysis model of the whole life cycle mechancial properties of the CFST columns subjected to eccentrical load is established,the whole process of loading behavior and working mechanism are analyzed in detail.Finally,the bearing capacity parametric studies are conducted in terms of the initial stress coefficient ?,ratio of concrete gap ?,the long-term load ratio n and eccentricity.The results show that the influence of eccentricity,initial stress coefficient and ratio of concrete gap on bearing capacity is not negligible,the long-term load ratio is less than that.(3)For only considering initial concrete imperfection of square concrete filled steel tube short column subjected to axial load of mechanical properties is analyzed,it is concluded that when the ratio of concrete gap ? is less than 0.1%,the bearing capacity of influence is neglected,so the whole life cycle isn't be considered.Then,the analysis model of whole life cycle mechancial properties of the square concrete filled steel tube short column is established,the whole process of loading behavior and working mechanism are analyzed in detail.The bearing capacity parametric studies show that the initial stress coefficient and the long-term load ratio have no obvious influence on the bearing capacity.For only considering initial concrete imperfection of square concrete-filled steel tube long column subjected to eccentrical load of mechanical properties is analyzed,it is concluded that when the ratio of concrete gap ? is less than 0.1%,the bearing capacity of influence is less,so the whole life cycle isn't be considered.Then,the analysis model of whole life cycle mechancial properties of the square concrete filled steel tube is established,the whole process of loading behavior and working mechanism are analyzed in detail.The analysis of bearing parametric studies show that the influence of eccentricity,initial stress coefficient and long-term load on bearing capacity can't be ignored.