Should EBF_s Be Preferred Over CBF_s in EQRD?

Steel buildings are getting popular because of their transportability, reusability and long life due to their maintainability. Earthquakes cause significant damage to the buildings. The extent of this damage is directly proportional to Inter-Storey Drift (ISD). Concentric Braced Frames (CBF) and Eccentric Braced Frames (EBF) are two commonly used braced frame systems that limit the ISD by increasing the building’s lateral stiffness. This study is divided into two segments. The 1st section presents an overview of existing literature on EBF, with a primary focus on works that demonstrate EBF’s superiority over CBF. This section delves into matters related to EBF, such as energy dissipation through ductile link behavior and the potential for substantial floor deflection. In 2nd part, the performance of CBF and EBF is compared in relation to ISD and energy dissipation. Four steel buildings with chevron (inverted V) braces [one each for CBF, EBF_0.4 (link length 0.4 m), EBF_0.6 (link length 0.6 m), and EBF_0.8 (link length 0.8 m)] have been modelled in SAP 2000 and designed as per the guidelines of IS 800 2007 and IS 1893 2016, keeping design base shear constant in all four models. Non-linear Time history analysis (NLTHA) is executed to conduct a comparative assessment of ISD in all the above models. The comparison of energy dissipation is based on the total strain energy capacity of CBF braces and EBF links. From this study, CBF are found to be performing much better than EBF.