A beam-column fiber element for the large displacement, nonlinear inelastic analysis of Concrete-Filled Steel Tubes (CFT) is implemented. The method of description is Total Lagrangian formulation. An 8 degree of freedom (DOF) element with three nodes, which has 3 DOF per end node and 2 DOF on the middle node, has been chosen. The quadratic Lagrangian shape functions for axial deformation and the quartic Hermitian shape function for the transverse deformation are used. It is assumed that the perfect bond is maintained between steel shell and concrete core. The constitutive models employed for concrete and steel are based on the results of a recent study and include the confinement and biaxial effects. The model is implemented to analyze several CFT columns under constant and non-proportional fluctuating concentric axial load and cyclic lateral load. Good agreement has been found between experimental results and theoretical analysis.
[1]
Mjn Priestley,et al.
STRENGTH AND DUCTILITY OF CONCRETE BRIDGE COLUMNS UNDER SEISMIC LOADING
,
1987
.
[2]
Douglas A. Foutch,et al.
Behavior of RC Columns under Nonproportionally Varying Axial Load
,
1990
.
[3]
Hanbin Ge,et al.
Strength analysis of concrete-filled thin-walled steel box columns
,
1994
.
[4]
Philip F. Boyd,et al.
Seismic Performance of Steel-Encased Concrete Columns Under Flexural Loading
,
1995
.
[5]
Jerome F. Hajjar,et al.
A distributed plasticity model for cyclic analysis of concrete-filled steel tube beam-columns and composite frames
,
1998
.
[6]
Jerome F. Hajjar,et al.
A distributed plasticity model for concrete-filled steel tube beam-columns with interlayer slip
,
1998
.