Finite Element Analysis Of Bias Mechanical Behavior Of Circular Steel Tube Recycled Concrete Composite Columns

With the acceleration of the modernization process,the extensive use of concrete has led to the excessive exploitation of non-renewable resources such as sand,gravel and the significant pollution of the abandoned concrete to the environment,making research on recycled concrete increasingly important.However,since the mechanical properties of recycled concrete are lower than ordinary concrete,recycled concrete materials are generally applied to non-structural systems.To make more extensive use of recycled concrete,scholars have proposed a combination of steel and recycled concrete.The round steel tube type steel recycled concrete composite column combines the good ductility of the steel and the good compressive capacity of the recycled concrete,and effectively compensates for the problem that the external steel tube of the steel tube recycled concrete column is prone to local buckling and the construction of the steel recycled concrete column is complicated.The project has a good application prospect.Based on the experimental study on the bias mechanical properties of the circular steel tubular steel recycled concrete composite column,the finite element analysis of the bias mechanical properties of the composite column was carried out by using ABAQUS software.The main research contents are:①In order to analyze the bias performance of the round steel tube steel recycled concrete composite column,the composite column finite element model is established by using the material data of the combined column and the bias test data.②The finite element calculation results and experimental results of the composite column are compared to verify the validity of the numerical model established in this paper.③Using the calculated stress and strain cloud images to analyze the failure modes and stress changes of the components of the composite column under eccentric compression.The combined column steel first yields,and then the round steel pipe yields.Finally,the recycled concrete on the compression side is crushed and destroyed,and the laterally-recycled concrete produces many transverse cracks,and the whole test piece is bent toward the pressure side;④TPerform parameter expansion analysis on the combined column.The results show that the initial stiffness and bearing capacity of the composite column decrease with the increase of the replacement rate of recycled aggregate,and the maximum decrease is about 10.1%;The ratio of diameter to thickness,eccentricity,slenderness ratio and strength of recycled concrete have great influence on the bias performance of the combined column;Compared with the section steel,the increase of the strength of the round steel pipe has a greater influence on the bias performance of the combined column;The section of the steel section has little effect on the bias performance of the combined column.Referring to the relevant specifications,the empirical coefficient method is used to consider the influence of parameters such as eccentricity,slenderness ratio and regenerative aggregate replacement rate on the biasing capacity.The calculation formula of the bias bearing capacity of the circular steel tubular steel recycled concrete composite column is obtained by fitting.Comparing the formula calculation results with the experimental results,the obtained calculation formula can provide reference for design.