Study On Compressive Behavior Of Round Steel Tube Concrete Composite Special-shaped Column

T section of round steel tube concrete special-shaped column is made up of four round steel pipe concrete column through compose connection combination special-shaped column section,based on the basis of the research on the square steel tube concrete special-shaped columns,the round steel tube concrete composite special-shaped columns,round steel tube concrete compression performance of the concrete filled steel tube is superior,for instance,has a high bearing capacity,plasticity and toughness of concrete filled steel tube is good,it can realize the factory prefabrication construction site after assembled,fireproof performance and structure seismic performance is superior,has many advantages,such as green economy,in the future field of prefabricated houses and prefabricated steel structure building,It is likely to become a mainstream general building structure type,in line with the future trend of green building development.The section forms of special-shaped column mainly include L-shaped column,T-shaped column and cruciform column.The research work on the mechanical performance of the special-shaped column with circular steel-tube concrete composite is relatively less.This paper mainly studies the special-shaped column with t-shaped section.1)The ultimate failure of long columns under eccentric compression is designed and completed.The test steps and the recording test process are introduced.The deformation characteristics and process of the members are analyzed.The mechanical performance of concrete filled steel tubular column limbs is also included.The load-displacement curves and load-strain curves of the four specimens are drawn through the data of the tests.And comparative analysis.The results show that under eccentric loading,each column limb of concrete filled steel tube is in the state of axial or small eccentric compression.Under different eccentric loading positions,the ultimate failure states of the four specimens are different,and the ultimate failure bearing capacity of the four specimens are also different.The ultimate failure states of the four specimens are overall bending failure.The limbs show bending and buckling damage.2)The finite element analysis software is used to build the model according to the size of the test specimen,and the finite element simulation results are compared with the actual test results.The difference between the finite element analysis results and the test results is not significant.Within acceptable range,the feasibility of the finite element simulation analysis of the compression-bending test of T-section concrete filled circular steel tubular composite special-shaped columns is verified.On this basis,the coagulation of the concrete filled circular steel tubular composite columns is the influence of soil strength,steel strength,different steel content,different load eccentricity and different connecting modes between columns on the stability bearing capacity of eccentric action is discussed.3)This paper introduces the corresponding calculation methods of different theories of stability bearing capacity of T-section concrete filled circular steel tubular under eccentric compression,simplifies the composite special-shaped column structure into space parallel composite truss,determines its conversion slenderness ratio,checks the practical application of compression-bending stability coefficient in different codes,so as to recommend it for future practical projects.