Research On The Prefabricated Structural Members And Joints Of Steel Tube Filled With Foamed Concrete

The application of CFST structure in practical engineering is more and more extensive,such as long-span bridges,multi-storey and high-rise buildings,its advantages of high bearing capacity and good seismic performance are particularly prominent in engineering application;however,its disadvantages of self importance and high cost also limit the scope of application of CFST structure,such as in middle and low-rise buildings,the requirement of bearing capacity is not high Within the range of meeting the requirements of bearing capacity,compared with other structures,concrete-filled steel tubular structure is of great importance and high cost.Therefore,this paper refers to an engineering case of an assembled frame structure,uses the foamed concrete structure of steel tube,applies it to the components of the frame structure uses the ABAQUS finite element software to analyze the mechanical properties of its columns and beams,and combines the theoretical knowledge to select a reasonable column beam component form,section size and material model.Select a reasonable joint form,and use ABAQUS finite element software to analyze its seismic performance,to verify whether the selection of joints is reasonable.The research content of this paper is as follows.(1)Referring to the section form and size of a frame structure,four section forms of columns are designed: square steel tube foamed concrete,round steel tube foamed concrete,square hollow sandwich steel tube foamed concrete and round hollow sandwich steel tube foamed concrete Analyze and study their respective mechanical characteristics.Considering the influence of the width thick Ness ratio,the strength of steel tube and the strength of foamed concrete on the lifting rate of the bearing capacity of the four section columns compared with the empty steel tube columns under axial compression and eccentric compression,and using ABAQUS finite element software to analyze,the conclusion is as follows.(2)Referring to the beam section form and size of a frame structure example,three different beam sections,I-beam,I-beam and rectangular section steel beam,are designed respectively,which are composed of composite foam concrete beam,box section steel tube foam concrete beam,and the stress analysis is carried out by using the finite element software to select the reasonable member form and section scale.(3)Referring to the beam column joint form and size of a frame structure,the joint connection mode of outer reinforced ring plate is designed.The stress analysis of the middle and side joints of the frame structure is carried out by using ABAQUS finite element software,and the influence of the wall thick Ness of steel tube and the strength of foamed concrete on the seismic performance of the joint is considered.The results show that:(1)The ratio of width to thick Ness and the strength of foamed concrete have the greatest influence on the lifting rate of the bearing capacity of the columns under axial compression and eccentric compression,while the influence of the strength of steel pipes is relatively small.The outer steel pipe is a column with square steel pipe section,and the thick Ness of the outer steel pipe wall should not be too thin;the outer steel pipe is a column with circular steel pipe section,and the thick Ness of the outer steel pipe wall should not be too thick,and should not be used for large bias components.(2)The foam concrete filling can increase the stiffness of the compression flange of the steel beam,make the force of the beam more uniform,and has little effect on improving the shear strength and the maximum deflection of the beam.(3)In a certain range,the greater the wall thick Ness of steel tube,the seismic performance of the joint is The better the strength is,the slower the stiffness degradation is,the better the ductility is.However,as the wall thick Ness of the steel tube continues to increase,its seismic performance has not changed much;the change of the strength of foamed concrete has little impact on the seismic performance of the joint.