Seismic Response of Adjacent Steel Frames Linked by Friction Dampers

When an earthquake happens, besides of some direct effects on the structures, some indirect factors can lead to damage to the structure. One of these indirect factors is pounding that occurs between two adjacent structures because of out-of-phase vibration. The simplest way for the elimination of earthquake-induced pounding is to have a proper gap between the two structures. However, this method is not applicable in all cases, and we should search for other methods that can reduce the pounding effects. Linking the two adjacent structures with different elements like friction dampers (FDs) is one of the applicable strategies that can be studied. A friction damper (FD) absorbs energy by friction, and the slip force is the most important factor in these dampers. In this study, the effect of pounding on adjacent frames with different heights and also the effect of considering friction dampers with optimum slip force that are distributed uniformly in the stories, have been discussed. It is concluded that pounding finally results in decreasing of the responses of the low-rise frame and in increasing of the responses of the high-rise frame. It is also revealed that linking the dampers does not reduce pounding effects in all cases, and their performance in reducing or increasing of responses of the frames belongs to characteristics of the adjacent frames and the acceleration time history.