Experimental and seismic analysis performance of three-core buckling restrained braces

In this paper, in order to improve the seismic behavior of BRBs, buckling-restrained braces with three parallel cores with different yield stress have been suggested and introduced. The buckling restrained braces were made in one and three steel core with the same tensile and compressive capacity. These braces were subjected to cyclic tensile and compressive loads in the laboratory under the ATC-24 loading protocol. Hysteresis cyclic performances of each brace were obtained and examined. Then, the one and three core buckling braces were placed diagonally in a steel moment frame and their seismic performance and response modification factors were obtained using adaptive pushover analysis. The results indicated that the three core brace has 16.3% and 8.8% higher energy absorption and damping capacity. In addition, the damping in the three-core brace in drift 2.5% is 8.8% higher than the one core brace. Mean value of response modification factors for steel moment frame with one-core brace is 8.11 and steel moment frame with three-core brace is 9.14. In conclusion, the three-core brace has higher energy absorption and damping capacity and the ductility of the steel moment frame with the three core brace is higher than that of the frame with the one core brace, which presented the three-core brace has more acceptable seismic performance and is highly recommended for rehabilitation