Research Of Test On The Shear Resistance Of Concrete-Filled Steel Tube Column

Concrete-Filled Steel Tube (CFST) is a type of composite structure material that the concrete is filled into thin-wall steel circular steel tube. The fire-resisting limit of CFST components is longer than steel structure and execution of works is easier, together with high bearing capacity, good plasticity and ductility. CFST is widely used in building structure such as one-layer and multi-layer factory building, various bracket, super high-rise building and bridge structure. The study of CFST further becomes hot topic due to its superior earthquake-resistance performance. Meanwhile, the definition of CFST shearing resistance becomes study topic that interests many scholars.The subject is a part of "steel-concrete composite structure design research of China Academy of Building Research. Based on shear resistance tests of 54 CFST columns, load-displacement curves and stress-strain curves of CFST columns were presented under the action of shear force. Visa this study, explicit cognition was generated about the damage process of CFST columns; This paper analyzed the results of test and discussed some parameters such as confinement index, shear span ratio and axial compression ratio that influence the shear resistance, studying emphatically the influence of shear span ratio and axial compression ratio on shear resistance. According to test results, this paper regarded the confinement index , shear span ratio , axial compression ratio u and the fcAc of concrete as characteristic parameters and brought forward the calculation formula for shear resistance of CFST columns by multivariate linear regression method. In addition, based on the theory formula of the shearing resistance in the document1'1 this paper ran a envelope curve of shear resistance, and considered the influence of shear span ratio and axial compression ratio, at the same time a practical and simplified formula was put forward. In the end, computer simulation of test with ANSYS was given, together with the load-displacement curve and shearing resistance. As a result, this test well conformed to the computer simulation analysis.