Abstract
The experimental study was made on the elasto-plastic behavior of tensile braced rigid frame for the purpose of obtaining restoring force characeristics of low steel structures. Alternating horizontal force is applied at the point of second floor under a constant vertical load, paying attention to the behavior of two columns subjected to varing axial forces. Test specimens are consisted of one-story one-bay rigid frames with wide frange sections and braces of round steel bars. Relations between shear force and displacement in each column were investigated by numerical analysis. According to this theoretical results, the elastc-plastic behavior of two columns are obviously different; one is subjected to additional tensile force and the other by additional compressive force. From these results, it is found that the restoring force characteristics of braced frames are stable but hysteresis loops in each columm become unstable because of the additional compressive force.
