Study On The Constitutive Relationship And Static Performance Of Stainless Steel-High-Strength Concrete-Ordinary Steel Hollow Composite Columns

With the rapid development of our country’s economy,the development of building structures has also transformed into lightweight and high efficiency.Stainless steel-high-strength concrete-ordinary steel hollow composite column structure has become a hot spot in the field of new materials and new structures.Compared with the traditional steel tube concrete structure,the stainless steel-high-strength concreteordinary steel hollow composite column structure changes the restraint mechanism of concrete,and has the characteristics of large turning radius and good stability.In addition,the use of stainless steel pipes has high corrosion resistance.Based on the characteristics of high strength,corrosion resistance,and low maintenance cost of the combined column,it is widely used in various fields of life.The study of the static performance of the combined column can provide a theoretical basis for actual engineering.Based on the axial compression experiment and ABAQUS finite element simulation,this paper conducts related researches on the static performance of stainless steel-high-strength concrete-ordinary steel hollow composite columns.The main work is as follows:(1)Designed and completed the axial compression experiment of 9 stainless steelhigh-strength concrete-ordinary steel hollow composite column specimens,and analyzed the influence of the hollow rate and the strength of the high-strength concrete on the bearing capacity of the axial compression specimens.The results show that both the hollow rate and the strength of the high-strength concrete play an important role in the bearing capacity of the specimen.The bearing capacity of the specimen decreases with the increase of the hollow rate,and increases with the increase of the strength of the high-strength concrete.(2)Based on four commonly used core concrete constitutive relationship models for finite element simulation,combined with the comparative analysis of test loaddisplacement curves,the finite element simulation curves of Shan-Tong Zhong model and Lin-Hai Han model are far behind the experimental curve after reaching the ultimate bearing capacity.The effect of the anastomosis is poor.The stress value of the Liu-Gho model finite element simulation is small,so its bearing capacity is much smaller than the experimental value.The finite element simulation curve of the Liu Wei model is the closest to the experimental curve,so the Liu Wei constitutive relationship model has the best agreement..A finite element model is established based on Liu Wei’s constitutive relationship for verification,and the ultimate bearing capacity and failure state are more consistent with the experiment;therefore,the Liu Wei core concrete constitutive model is suitable for composite column finite element simulation.(3)Establish a finite element model based on the ABAQUS finite element software to analyze the influence of different parameters on the mechanical properties of the composite column;for the axial compression of the component,the component bearing capacity decreases with the increase of the hollow rate and the inner tube diameter-thickness ratio.The strength of high-strength concrete and the nominal steel content increase;for eccentrically compressed components,the inner pipe diameterthickness ratio and hollow ratio have little effect on the bearing capacity of the component,while the eccentricity,high-strength concrete strength and nominal steel content have little effect on the bearing capacity of the component.It has a greater impact.The bearing capacity increases with the increase of the strength of the highstrength concrete and the nominal steel content,and decreases with the increase of the eccentricity.By analyzing the eccentric pressure performance of the composite column,the calculation formula for the bearing capacity of the stainless steel-high-strength concrete-ordinary steel hollow composite column member is determined and verified.