Study On Concentric Compressive Behavior Of Concrete-Filled Aluminum Alloy Circular Tubular Stub Columns

Because of the advantages of high bearing capacity,good plasticity and toughness,good economic benefits and so on,the concrete filled steel tube structure has developed rapidly in the construction industry.However,the corrosion resistance of the external steel tube of concrete filled steel tube is poor,so it is necessary to carry out anti-corrosion treatment on the steel tube in the use process,which leads to the increase of maintenance cost in the later period.The series of 5000 and 6000 aluminum alloys have relatively good corrosion resistance.Aluminum alloy tube eoncrete should have good mechanical properties as concrete filled steel tube,which provides an alternative structural scheme to alleviate the corrosion problem.In this paper,experimental study,finite element analysis and theoretical analysis of the basic performance of aluminum alloy tubular concrete columns are carried out,and the following aspects of research work are carried out concretely:(1)Ten concrete stub columns with aluminum alloy tubes were tested under axial compression.The failure modes of the specimens were summarized.The relationship between the axial force and longitudinal strain curves of the concrete with aluminum alloy tubes,the relationship between the axial force and strain curves of the concrete with aluminum alloy tubes,the bearing capacity of the specimens and the axial compression stiffness of the concrete columns with aluminum alloy tubes were obtained.(2)Using ABAQUS software,a reasonable finite element model is established to analyze the mechanical properties of Al-alloy tube concrete short columns under axial compression.The stress-strain curves of core concrete suitable for ABAQUS finite element simulation are obtained by comparing the finite element analysis results with the experimental results.Based on the empirical finite element model,the parameters of the axial compressive behavior of aluminum alloy tubular concrete columns are analyzed to determine the influence of the strength of aluminum alloy,concrete strength and hoop coefficient on the axial compressive bearing capacity.(3)Based on the ultimate equilibrium theory,the formula for calculating the bearing capacity of concrete filled steel tubular columns under axial compression is obtained by modifying the existing formula for the bearing capacity of concrete filled steel tubular columns under axial compression.