Seismic behavior of special shaped column composed of concrete filled steel tubes

This paper experimentally investigated the behavior of a special shaped column composed of concrete-filled steel tubes (SCFST column) subjected to a constant axial load and a cyclically varying flexural load. The effects of both the axial compression ratio and the length to width ratio on the behavior (stiffness, strength, ductility, and energy dissipation) of SCFST columns were studied. The asymmetry character of the column was studied. The connection plate was an important member transferring shear force. The mono columns of SCFST columns worked together well and the seismic behavior of SCFST columns was good. An increase of the axial compression ratio increased the stiffness with a decrease of energy dissipation ability, ductility, and bearing capacity. On the other hand, an increase of the length to width ratio led to an increase of energy dissipation ability and ductility and a decrease of stiffness and bearing capacity. Furthermore, a finite element analysis was also carried out to simulate the behavior of SCFST columns and the test results agreed with the results of finite element analysis. (C) 2012 Elsevier Ltd. All rights reserved.