Seismic Performance Evaluation of Buckling-Restrained Bracing Systems with Lower Grade Steel Core Based on Pushover Analysis

Nonlinear dynamic analysis methods are very time-consuming and require consideration of a set of ground excitations and have their own complexities, but nonlinear static analysis methods can be considered a suitable option for evaluating the seismic performance of structures. The conventional pushover method, as the first and simplest nonlinear static analysis method, has been able to occupy a good position in the last few years among different methods. The aim of this research is to investigate the behavior of buckling braces with a mild steel core and structural steel. For this purpose, three ۴-, ۸- and ۱۲-story structures with buckling braces were designed based on valid codes and all seismic criteria were also controlled. Then, a two-dimensional frame of them was examined and then the results of nonlinear static analysis in two cases of braces with a mild steel core and structural steel were compared. The results of nonlinear static analysis indicate that energy absorption and initial stiffness are higher in mild steel models, and also that the ductility of mild steel frames is higher due to the number and process of plastic joint formation in the models.

کلیدواژه ها:

Buckling brace ، Lower grade steel ، energy absorption ، nonlinear static analysis ، ductility