Abstract
The inelastic behaviour of steel frames under monotonous or alternating horizontal force was experimentally studied, using nearly full scale models. The test program consisted of four specimens of one bay one story frames. Two of them were tested under constant vertical loads on the columns. Test frames were end fixed rigid frames of continuous welded construction, using mild steel rolled wide flange sections. In this experiment new apparatus were developed to prevent the out-of-plane deformation and twisting of specimens, and they have shown favorable results on the effect. It was generally observed that the test results do not differ remarkably from those of miniature or medium size models tested previously to this experiment. The horizontal force did not decrease according to local buckling phenomena of member sections. However, in the case that the frame was subjected to alternating horizontal force under constant vertical loads on the columns, the horizontal force decreased owing to out of plane deformation of frame members induced by local buckling. The experimental behavour are fairly well predicted by analysis which are considered the effect of repetition of horizontal force on the inelastic behaviour of frames.
