Effect of link on eccentrically braced frames

TL;DR: In this article, the authors investigated the seismic performance of three 5, 10 and 15-storey steel structures with moment-resisting frames designed three dimensionally in ETABS 2015 application based on first edition of Iranian Standard 2800.

TL;DR: In this article , a self-centering, Y-inverted, eccentrically braced frame (SC-YEBF) is proposed, which combines the lateral load resisting benefits of YEBF including strength, stiffness and energy dissipation capacity with the recentering capacity of post-tensioned high strength steel strands used at beam-to-column connections.

TL;DR: In this paper , the authors investigated the effect of eccentricity as 15 cm and 25 cm on the reinforced concrete braced frames of 80 cm x 100 cm in dimension compared to the V-type of Concentric Braced Frame (CBF).

Abstract: Eccentrically braced frames (EBFs) are desirable seismic load resisting systems as they combine the high elastic stiffness of concentrically braced frames with the ductility and stable energy dissipation of moment resisting frames. EBFs with links attached to the columns are particularly appealing for architectural flexibility as they provide multiple locations for placement of doors and hallways. However, previous research has shown that link-to-column connections are prone to failure at low drift levels, due to their susceptibility to fracture at the link flange-to-column welds. This paper investigates the application of the reduced beam section concept for links in eccentrically braced frames to enhance the ductility of link-to-column connections. A design procedure for link section reduction is proposed and preliminary finite-element analyses are conducted on a shear link with various reduced section geometries. A parametric study performed on an array of links having various cross sections and lengths suggests that the reduced link section may substantially reduce the plastic flange strains at the link ends, which can improve the fracture life. The reduction in plastic flange strains is found to be significant for all links, with larger reductions for intermediate and flexural links. Furthermore, the detrimental kinking deformation of the flanges, caused by the large rotation demands in shear links, is moved away from the column face when reduced sections were used. While the analysis results show promise, experimental verification is recommended before the proposed design procedure can be implemented in practice.