Performance of Elliptical Hollow Sections under Combined Compression and Cyclic Bending

Abstract

This paper comprehensively discusses the potential of applying elliptical hollow sections (EHSs) for seismic regions. The study commenced with an experimental investigation of 12 EHS beam-column specimens under combined compression and uniaxial cyclic bending, where the main test parameters were section slenderness, axial load ratio, and loading direction. Local buckling was found to be the main failure mode for all specimens, and strength, ductility, and energy dissipation greatly depended on the varying test parameters. The manufacturing of the specimens was also looked into, and the resulting material properties and residual stresses were examined. Following the experimental study, a numerical investigation was carried out. The numerical models were validated against the experimental data with good agreement observed, enabling a further parametric study to be conducted taking account of a wider range of parameter matrices. The influences of a spectrum of geometric and material properties on section behavior were evaluated, and, based on the available data, a ductility-oriented design approach for EHSs was proposed. The imperfection amplitude and imperfection shape were found to moderately affect the behavior of EHSs.