Effects of Six Earthquake Scaling Methods on Drift Demand Distribution of Buckling Restrained Braced Frames: A Comparative Study with Endurance Time Method

Abstract

Abstract This paper investigates the effect of six different methods of scaling ground motion records on the response of maximum nonlinear displacement and maximum acceleration of frames equipped with Buckling Restrained Braces (BRBs). The study focuses on achieving the target range of the design and compares the average values obtained with the Endurance Time (ET) method. To achieve this objective, two steel bending frames, consisting of three and nine stories, respectively, which were designed for the SAC project, were selected. These frames were modeled and validated using OpenSees software. To ensure the model's accuracy, the BRB elements were modeled using the Steel02 steel material, along with Pinching4 and Fatigue Material, to make them more compatible with reality. The model was then validated using experimental results. The aim of this research is to evaluate the accuracy and dispersion of various scaling methods of ground motion records in calculating the relative displacement, maximum acceleration, and base shear of BRB frames. The study also aims to determine the most suitable scaling method based on its efficiency and accuracy in a parametric manner. A total of 530 nonlinear dynamic analyses were conducted, and the average results of drift and acceleration obtained from the scaling methods were compared to the results obtained from the endurance time method. The findings suggest that the Endurance Time Method provides accurate results for short structures, but it requires correction for tall structures. Additionally, the IM4 scaling method has unique properties on BRB-equipped frames, making its use logical in the process of obtaining the synthetic ET method record.