An Experimental Study on the Inelastic Behavior of Steel Frames with a Rectangular Cross-Section Subjected to Vertical and Horizontal Loading

Abstract

An experimental study was made of the behavior of single bay three-storied frames, using 1/30-scale models with rectangular cross-sections. Frame models were cut from a sheet of mild steel. A varying horizontal force and constant vertical loads were applied at the top of columns. The horizontal force-displacement relations show the remarkable dependence of frame behavior on the existence of vertical loads ; the behavior is characterized by a gradually increasing lateral displacement, first under a growing load and later under a diminishing load, the slope continuously decreasing in the horizontal force-displacement relation. Elastic-perfectly plastic type of analysis underestimated the restoring force in the large deformation range. An approximate elastic-strain hardening analysis was attempted in order to gain access to the real behavior of frames, and a reasonable agreement is seen with the experimental results.