ABSTRACT
The behavior of full-scale connections typically represented by a nonlinear momentrotation curve is based on the various response mechanisms of individual connection components (Leon, 1997; Mehrabian et al., 2009; Shi et al., 1996; Faella et al., 2000; Kim et al., 2008). The behavior of each connection component under monotonic loads is fairly simple to simulate with bi-linear or tri-linear stiffness expressions. However, the interaction between connection components is not always easy to predict because they are not behaving independently anymore within the connection. Moreover, this problem is compounded for the case of large cyclic deformations where careful checking on permanent deformations is needed (Rassati et al., 2004). Therefore, the connection models are very complex and require a large number of stiffness components. For the computational convenience, structural connections designed in the past were assumed to be extreme behavioral ones, i.e., the simple pinned connections and the ideally welded connections, and therefore the necessity for the actual moment-rotation response of the connection was very limited (Leon et al., 1998; Green et al., 2004). In reality, most connections including bolted connections exhibit the intermediate behavior between two extreme cases.
