The Seismic Performance Of Concrete Filled Steel Tubular Laced Column-Steel Beam Composite Frame

Abstract:Concrete filled steel tubular(CFST) laced columns is a new type of composite column which takes material advantage of CFST columns and section advantage of lattice columns. Thus it is widely used in engineering circles. However, the research on the seismic performance of concrete filled steel tubular laced column-steel beam composite frame is so deficient that the application and popularization of this superior structure form will be limited. In order to study on the seismic performance of CFST lattice column-steel beam composite frame, with the help of ABAQUS, the main contents are mainly as follows:(1) Hysteretic behavior research under cyclic loading for a CFST lattice column-steel beam composite frame is conducted to check the reliability of this model. The influence of parameters, including the axial compression ratio, steel ratio and stiffness ratio of beam to column, is mainly analyzed. Results show that, as the axial compression ratio increases, the structure’s bearing capacity reduces, ductility gets worse, energy consumption capacity declines, while the influence of steel ratio and stiffness ratio of beam to column is opposite.(2) Modal analysis for a two layers of CFST lattice column-steel beam composite frame is conducted to get its natural vibration frequency, while the influence of steel ratio and stiffness ratio of beam to column is mainly analyzed. The dynamic characteristics of this structure are turned out to meet the requirements of relevant norm through the analysis of the first six vibration mode.(3) Dynamic time history analysis is carried out to obtain the response of this structure under frequently occurred earthquakes, the differences in seismic response of this structure influenced by different unidirectional seismic wave and different parameters, including the axial compression ratio, steel ratio and stiffness ratio of beam to column, are analysed. Results show that, as steel ratio or stiffness ratio of beam to column increases, seismic response of this structure reduces and the speed gradually slow down, while along with the increasement of axial compression ratio, seismic response decreases first and then rises.(4) Based on the results of finite element analysis and the structure’s cost performance, the reasonable value of steel ratio is8%-12%and stiffness ratio of beam to column is0.6-1.0.