Publication
This paper discusses the findings from a large-scale experimental program that characterized the hysteretic behavior of typical steel wide-flange columns in steel moment-resisting frames (MRFs). The test specimens were tested in a cantilever configuration with a fixed point of inflection. The main testing parameters included various lateral and axial loading histories, the applied axial compressive load and the local slenderness of the cross-section. It is shown that (a) steel columns subjected to high compressive axial loads (i.e., larger than 50% of their critical axial load) should not be treated as forced-controlled elements as suggested by ASCE/SEI 41-13;(b) the axial shortening is an important deterioration mode that should be explicitly considered as part of the seismic design process of columns in steel MRFs; (c) end columns are characterized by non-symmetric hysteretic behavior due to the dynamic overturning effects during an earthquake. The test program provided unique experimental data that characterized the monotonic backbone curve of steel columns through the loss of their axial load carrying capacity under various levels of axial load ratios.