Study On Mechanical Properties Of Circular Steel-Concrete-CFRP-Concrete Solid Composite Short Columns Under Axial Compression

CFRP composite material has been widely used in aircraft, space, bridges and other constructional engineering for its high tensile strength, light weight, good insulation performance, and good corrosion resistance. Particularly in recent years, with the deep research of CFRP and its price reduction, people pay more and more attention to its application in constructional engineering. But because of its relatively resistance to fire poor, the use of CFRP in some special environment is restricted. All the existing combination columns including CFRP do not consider this disadvantage about resistance to fire, so in order to offset CFRP's this shortcoming and improve the bearing capacity of the column, this thesis on a new component of Steel-Concrete-CFRP-Concrete solid composite column is researched(abbreviation:SCCC column).As a new kind of component, various aspects performance all need for research. This thesis uses experiment and finite element simulation to research mechanical property of Steel-Concrete-CFRP-Concrete solid composite column. By comparing Steel-Concrete-CFRP-Concrete solid composite column to circular section common steel concrete, this paper introduces making process of the specimen, loading device, loading method and measurement method, and intuitive observed destructive form, and preliminary understanding to mechanical characteristics of this new structure can be got. By experiment we can get that the relationship of the horizontally and vertically strain to load and the relationship between load and displacement under the axial pressure, comparatively analyzed mechanical properties of component, based on the three stress failure mechanism of concrete, working mechanism of Steel-Concrete-CFRP-Concrete solid composite column under axial load is analysed. Raise rates of bearing capacity are compared on the same conditions by setting different CFRP layers, coordination abilities of round steel tube, concrete and CFRP pipe are researched.Based on the section properties and interaction mechanism of, appropriate unit types are selected, material model and failure criterion, geometric parameters of test measured and material parameters are used to carry on the finite element analysis. Compared element results to experimental results, it shows that finite element analysis model of this paper is feasible to properties analysis of Steel-Concrete-CFRP-Concrete solid composite column under axial compression. Meanwhile, it can be perceived from Von Mises stress cloud picture of finite element, the mechanical characteristics of finite element model and theoretical analysis are same. Based on load-strain curve, the mechanical characteristics on different working stages of Steel-Concrete-CFRP-Concrete solid composite columns are analysed.Based on the results of finite element analysis results and test, working mechanism of Steel-Concrete-CFRP-Concrete solid composite column,we can know that along with the increase of internal CFRP pipe thickness, ultimate bearing capacity is improved greatly under the same condition. Finally exist formulations and tests are used to confirm bearing capacity formula of Steel-Concrete-CFRP-Concrete solid composite column, provide certain reference to future design and theoretical studies.