Unlike column-to-beam connections in reinforced concrete frames, column-to-beam connections are generally of the same type. Vertical load (D.L + L.L) and horizontal load (wind load, seismic load) are not the same in the upper and lower flange stress history. In the case of beams bonded to synthetic CFT columns, the tensile force is transmitted through the steel pipe column, and the compressive force is transmitted to the filled concrete, so the seismic performance is excellent even if the column has a relatively thin cross section. Also, in case of beam the composite CFT column, tensile force is taken by the steel pipe column, and the compressive force is caught by the inner concrete, and the shape of the column joint can be changed. In this study, the stress distribution of buildings is investigated according to the size and characteristics of the building, and the load history of the upper and lower flanges according to the building type is checked to show the structural possibility of the Asymmetric Diaphragms joint.

Recently, as the number of earthquakes has increased, the building structure standard has been revised in 2016. In order to minimize earthquake damage, steel frame is used as the most economical and efficient lateral resistance system. Also, when the steel braces are subject to Compressive load, which causes unstable behavior of the structure. In order to verify the compressive behavior of the reinforced Braces, structural performance tests were conducted with variables of slenderness ratio and the amount of reinforcement. This study investigates the structural performance of existing double - angle steel braces by reinforcing them with non- welded/assembled light-weight steel frames and proposes a suitable reinforced section.

The seismic design range for the national public facilities and power plant is expanded such as it becomes the earthquake Disaster Relief Act with the finance since 2008 as the seismic design concept is highly regarded, etc. The reinforcement of the brace is essential for the seismic performance security of the structure which is unable to be satisfied the current seismic design criteria. The tension brace in which the slenderness ratio is big was designed to the unique lateral force resistive element. And the buckling is generated in the first stage and it is unable to exhibit the structural capability. In this research, the buckling strength improvement the reinforcing method of the suggested tension brace tries to be verified through the experiment.