Finite element analysis of seismic performance of composite concrete-filled steel tube column-steel beam connection

The composite concrete-filled steel tube(CFST) column has high compression-bearing capacity,and especially good anti-collapse behavior in strong earthquake,which has been widely used in large-span bridge and super high-rise buildings recently.According to the experimental study on composite concrete-filled steel tube column-steel beam connection,and based on reasonable selection of constitutive relationship of material and failure criteria,the finite element model(FEM) was built by the software ANSYS,the mechanical properties of the connetion were researched under the low cyclic loading.The simulated hysteretic curves and skeleton curves are in good agreement with the experimental data,which verified the reasonableness of the finite element model.Stress analysis was cnducted by using FEM to study the failure mode and force transmission mechanism of the new connection system.Moreover,parametric studies were carried out to investigate the influences of the intensity of steel beam and external square steel tube column,the wall thickness of external square steel tube column and axial compression ratio of the composite CFST tubes column on mechanical behavior of the connection.The results presented give a reference to test design and engineering application of the new type of connection.