| As a composite structure,CFST has good plasticity and toughness and is widely used in bridge structures.Because of the large stiffness of the long axis of the circular end section,this type of section is very suitable for the pier column of the bridge structure with small transverse stiffness.As a new type of composite material,MPC composite has the characteristics of light weight,high strength and early strength,which is very suitable for the rapid construction of bridges at present.By combining the above three structures,a round-ended steel tube-MPC composite structure is formed,and the mechanical properties of the structure are studied systematically.This paper analyzes the mechanical properties of round-ended steel tube-MPC composite structure based on ABAQUS finite element analysis software.After determining the material constitution,element type,mesh partition,interface simulation and so on,the axial compression performance,bias performance and seismic performance of the composite structure of round-ended steel pipe-MPC are analyzed one by one.The finite element software ABAQUS is used to simulate the whole process of the round-ended steel tube-MPC composite structure under axial compression load,and the mechanical mechanism of the round-ended steel tube-MPC composite structure under axial compression load is systematically analyzed,and the difference between the structure and the circular end steel tube concrete is emphatically compared.furthermore,the parameter analysis of the round-ended steel tube-MPC composite structure is carried out to study the influence of different parameters on the axial compressive bearing capacity of the structure,and thus the calculation formula of the axial compressive bearing capacity of the round-ended steel tube-MPC composite structure is fitted.Secondly,the hoop effect of round-ended steel tube-MPC composite structure under the action of bias load is analyzed to clarify the reason that the bias bearing capacity of the structure is smaller than that of the axial compression bearing capacity.In the analysis of the influence factors of the structural bias bearing capacity,the bias reduction coefficient is introduced to determine the influence of each factor on the bias reduction coefficient,so as to fit the calculation formula of the structural bias reduction coefficient.Finally,the seismic behavior of round-ended steel tube-MPC composite structure is analyzed.The effects of steel type,section shape(with or without partition),wall thickness of steel pipe and axial compression ratio on the seismic performance of the structure are studied by simulation.Comparing and analyzing the seismic performance of round-ended steel tube-MPC pier,round-end steel tube concrete pier and round-end reinforced concrete pier,the results show that the seismic performance of round-ended steel tube-MPC pier is obviously better than that of the other two forms of pier. |
