Experimental Study of Connection Strength Effects in X-Type Braced Frames

Braced frames are popular a type of steel frames in Iran. In these structures different kind of braced are used to resist lateral loads and all connections are considered as fix-type connections. In practice great care is taken, but it is not possible to construct fully fix-type connections and they are partially fixed, however, to be on the safe-side this fixity is neglected.In this research, experimental behavior of the braced frame connection with scale of 0.5 under cyclic load has been investigated. This study has been performed under the same loading condition using three tests: 1- bare frame made of beam and columns; 2- frame with gusset plates; 3- x-braced frame (braced made of two U sections). Results show that connection in these type of frames, although neglected in calculations, have some fixity and with use of gusset plates this fixity becomes much more.