Design And Analysis Of Seismic Performance Of Buckling-Restrained Braced Frames

Because concentrically braced frames is an excellent lateral resistance system, they are common system in steel structures or reinforced concrete structures。But when endure press under earthquakes, traditional steel braces will buckle and lose capability. Whereas reinforced concrete structures have good capability of enduring press, their capability of pull is weak and the concrete is easily to breach. Buckling-Restrained Brace (BRB) offer lateral restriction to the steel core to avoid it to buckle, when being suffered big press or pull, and the steel core always can yield. By logical design, Buckling-Restrained Braces can keep elastic to afford big lateral stiffness with the main structure when under frequently-occurred earthquake action, and under strong shock can yield ahead to dissipate the earthquake energy then to protect the main structure. After strong shock, the unelastic distortion of main structure is small, it is easily to replace the broken braces. And most of the buckling-restrained brace can be used continuously.Firstly, it introduces the background and the current application of the Buckling-Restrained Brace Frames, then the existent problem and the main content of this paper in the first chapter of this paper. It introduces the conformation, theory of energy depletion, stiffness and basic computation theory of steel core parameter in the second chapter,characteristics of the Buckling-Restrained Brace Frames and design flow in the third chapter of this paper. In the fourth chapter, the design method is depicted, especially some nonlinear problems and resolvent. In the fifth chapter, firstly, a three-storey reinforced concrete frame structure is designed with conventional concentrically braced frames and Buckling-Restrained Braced Frames. Then it is approved the aseismatic capability of the Buckling-Restrained Braced Frames is best than other three structures with conventional concentrically braces by response spectra analysis, nonlinear time-history analysis and nonlinear static analysis. In the sixth chapter, a steel structure is analysed, the conventional concentrically braces of which are substituted by Buckling-Restrained Braces according to even stiffness principle. Then it is analysed by nonlinear time-history analysis and nonlinear static analysis to check up its aseismatic capability. As result, Buckling-Restrained Braces of the steel structure keep elastic to afford big lateral stiffness with the main structure under frequently-occurred earthquake and yield ahead to dissipate the earthquake energy under strong earthquake then to protect the main structure. The Buckling-Restrained Braced steel Frame is provided with well energy dissipation capability. The result of this paper will redound to generalize the Buckling-Restrained Braced Frames.