Seismic Design and Ductility Evaluation of Partially Concrete-Filled Steel Box Columns

This paper deals with the seismic design and ductility evaluation of partially concrete-filled steel box columns. The effects of residual stresses on seismic capacity prediction of partially concrete-filled steel box columns are investigated. Recently, Mamaghani and his co-workers have developed a seismic design method for ultimate strength and ductility evaluation of hollow and concrete-filled thin-walled steel tubular beam-columns [1]. The method involves an elastoplastic pushover analysis and definition of failure criterion taking into account local buckling ignoring residual stresses. In this study the method is modified for the effect of residual stresses. The application of the method is demonstrated by comparing the computed strength and ductility of some cantilever beam-columns with test results. The interaction between the effects of residual stresses and some important parameters, such as width-to-thickness ratio, column slenderness ratio and height of infill concrete, on the ultimate strength and ductility of thin-walled steel tubular beam-columns, are presented and discussed.