Investigation On Experiment And Mechanical Behavior Of Four-tube Concrete-filled Steel Tubular Laced Columns

The concrete-filled steel tubular (CFST) column is superior to other Structures in high bearing capacity,technology and economy. Because of these advantages, it has been adopted in industry factory and high-rise buildings widely. Therefore the domestic and international scholars have carried on by many researches on mechanics performance and design method of CFST structures. However, no yield point of the steel pipe filled with concrete are not involved; The model tests of concrete-filled steel tubular laced column are not many. The experiment and theoretical analysis about no yield concrete-filled steel tubular short column and CFST laced column have done. The primary parameters of ultimate load carrying capacity are analyzed. Formulas related to the ultimate load have been establishment. The main research content is as follows:(1) A total of CFST short columns under axial compression are tested. Steel tube of 9 specimens have no yield point, the other have obvious yield point. analysis were conducted for the destroy configuration,the stress-strain curves and the stress-Poisson ratio curves of composite materials . Calculation results from using the ANSYS software agree well with the test results. Define name- yield strength to the steel have no yield point. Apply the existing formula to calculate the CFST short columns have no yield point, the calculation results agree well with the test results.(2) A total of 4 four-tube CFST laced columns are tested, analysis were conducted for the destroy configuration,the stress-strain curves and the stress-Poisson ratio curves of composite materials .(3) The calculation formula for eccentricity reduction factor of 4 four-tube CFST laced columns has given. Calculation results from using the ANSYS software agree well with the test results. The calculation formula for slenderness ratio reduction factor has given also.