The Nonlinear Finite Element Analysis On Mechanical Properties Of High Strength CFST Under Axial Compression

In the new century society, the various disciplines go hand in hand, more and more new ideas are put forward by the majority of researchers, structural engineering is one of them. Steel-concrete composite structure is the new member in civil engineering structures, but by virtue of its features popularly in the majority of scholars. Currently each country for the study is different, developed countries and regions have been more perfect on common materials, various forms of theoretical and normative steel-concrete structure, and a succession of new materials, new forms of steel and concrete added to the specification, the addition of their existing structure has broad application to the reality of the project, such as large-span bridges, high-rise buildings. In China, from the beginning of the 1980s, steel-concrete structure has preliminary studies, is also in line with China standard of steel-concrete structure incorporated into the specification, and on this basis, scholars have proposed a " steel concrete unification" theory, however, these relatively mature theories and norms is not enough to make steel-concrete structure is more widely used in the country, only a small part of the more avant-garde, cutting-edge architectural structure were applied to obtain, so the majority of the scholars in china also need the courage to explore.CFST is one of many forms of concrete-steel structures. Although it has not the same binding strength steel for core concrete as circle, reinforced concrete bearing capacity no higher, but its own node is simple so the majority of scholars like it. With the development of modern science, technology and materials updating, in order to cope with today's challenges for building high-capacity, high economic efficiency and high utilization of the area, the majority of the CFST researchers also conducted in-depth research, and gradually increase the structural the complexity of the form, and gradually increase the strength of the material is the direction of research topics.Based on the above, the paper summarizes the development of home and abroad for high strength concrete filled high strength square steel tubular column. The innovation of the CFST structure is about the two materials changed to high-strength materials. In addition, we have made the nonlinear finite element analysis of the columns under axial compression, the analysis of typical examples of stress-strain curves for the working mechanism of high strength concrete filled high strength square steel Stub Columns, do an analysis studied at various stages of loading high-strength steel and high-strength concrete were assumed vertical load ratio compares the core of high-strength concrete and plain concrete stress high-strength concrete and ordinary concrete compressive strength of concrete under strain curve. Under the same confining factor raise the proportion of the middle section of the stress of high strength steel and high-strength concrete short columns under axial compression and strain distribution were analyzed. Finite element analysis for the strength of core concrete, steel yield strength, cross-sectional dimensions and steel ratio and other factors for the mechanical properties of high strength concrete columns with high-strength steel side effects of the law. Finally, the calculation formula of Square's of Europe and Japan put forward checking, comparing the error range for the future of high strength concrete filled high strength square steel tubular column under axial compression capacity calculation reference recommendations..Using software ABAQUS of nonlinear finite element analysis, HCFST under axial compression stress state load-deformation curves and the various factors on the mechanical properties of the specimen influence were analyzed. And analysis of the core concrete and the interaction between square steel tube, before reaching the limit load we get the concrete bearing the major part of vertical load, after which both bearing the vertical load ratio close to 1:1. Square tube and core concrete in force during stress situations and draw strength square steel high-strength concrete columns take full advantage of high-strength steel with high strength concrete compressive tensile characteristics of wood properties, while its ultimate capacity has been significantly improved, while high-strength steel tube axially loaded high-strength concrete post ductility is poor, but steel ratio, the greater the latter part of the larger residual capacity. This new type of composite structures for further research work provides a reference.