Structural performance of concentrically and eccentrically braced frame

Abstract

Indonesia is prone to earthquakes. Therefore, the building needs to be designed to withstand earthquake lateral force. One of the lateral-resistant elements is a steel frame system with bracing. There are two types of bracing based on its configuration, that is Concentrically Braced Frame (CBF) and Eccentrically Braced Frame (EBF). The objective of this research is to examine the capability (lateral resistance, plastic hinge mechanism, and ductility factor) of CBF and EBF. Structural analysis is performed using SAP2000 v.18. Pushover analysis is performed on Moment Resisting Frame (MRF), CBF, and EBF with various link lengths e = 0.4 m, 0.6 m, 0.8 m, and 1.0 m). The increase in lateral resistance resulting from the use of CBF is 74% and for EBF is 52% compared to MRF. The plastic hinge mechanism for CBF is marked by the formation of plastic hinges on bracing, while EBF is marked by the formation of plastic hinges on the links then beams and columns. The ductility factor for CBF is 45.75% smaller than MRF. While for EBF, the ductility factor is 18.20% smaller than MRF but 33.68% larger than CBF. Therefore, EBF is more ductile than CBF.