Research On Mechanical Performance And Design Method Of Concrete-filled Rectangular Steel Tube Subjected To Complexed Force

The concrete-filled rectangular steel tubular member is one of the section type of concrete-filled steel tubular(CFST) structures. The concrete-filled circular and square steel tubular members were researched much more than the rectangular CFST members. This paper study the performance and design approachof the concrete-filled rectangular steel tubular members under the bi-direction eccentric compression, torsion, shear, combined compression and torsion, combined bending and torsion, combined compression, bending and torsion, and combined compression, bending and shear.The main work can be summarized as follows:(1) A finite element model on concrete-filled rectangular steel tube was developed. The theoretical results are in good agreement with the experimental results. Parametric analysis are performed on concrete-filled rectangular steel tube under the bi-eccentric loading.(2) The concrete-filled rectangular steel tubular members were simulated under pure torsion and pure shear loading based on the FE model using ABAQUS. The theoretical results are matched well with experimental results. A practical design approach of ultimate strength for concrete-filled rectangular steel tubular members were given under pure torsion and pure shear loading based on a large scale parameter study.(3) The concrete-filled rectangular steel tubular members performance were simulated under combined compression and torsion and combined bending and torsion based on the FE model. The FEM results are matched well with the experimental results. Parametric Analysis on concrete-filled rectangular steel tubular members were performed under the combined compression and torsion and combined bending and torsion, respectively. A design interactive equation for concrete-filled rectangular steel tubular members under combined compression and torsion and combined bending and torsion were proposed, respectively.(4) The concrete-filled rectangular steel tubular members performance were simulated under combined compression, bending and torsion and combined compression, bending and shearing based on the FE model. Some experimantal reselts were verified the FEM results, and they are matched well each other. Parametric Analysis on concrete-filled rectangular steel tubular members were performed under the combined loading. The simple interactive equation for concrete-filled rectangular steel tubular members under combined compression, bending and torsion and combined compression, bending and shearing were proposed, respectively.