Effect of High Axial Load on Overstrength Factor of Intermediate Links in EBFs

Eccentric bracing frames (EBFs) are one of the most suitable seismic resistance systems due to their high strength, ductility, and energy dissipation. In some EBF configurations, due to loading patterns or structural geometry, the link member can be subjected to a high axial load. The presence of high compressive axial loads increases the occurrence of buckling and thus reduces both its strength and ductility. Most of the studies conducted have focused on short links, and as mentioned in the commentary of the AISC seismic regulations, the effect of axial load on the behavior of intermediate and long links has not been sufficiently investigated, which highlights the need for further study. In this research, numerical modeling is first validated by experimental results. Subsequently, the overstrength factor of intermediate links made from European I-shaped sections subjected to axial loads is examined. The results indicate that the overstrength factor of intermediate links is lower than the prescribed value of ۱.۵ in the provisions.

کلیدواژه ها:

Eccentrically braced frame ، Intermediate link ، Overstrength factor ، High axial load ، Finite element modelling