Dynamic Identification of a Three Story Steel Frame with Bolted Flange Joints

Previous studies show there are differences between experimental responses of bolted flange joint steel frames and those of the analytical models. In most of the cases these differences result from some geometrical or mechanical uncertainties, and in this specific structure, complex behavior of joints is one of these uncertainties. Therefore, knowing the real dynamic characteristics of this structure can help to predict its behavior under different conditions In this article, a three story steel frame with bolted flange joints and one bay in each direction was constructed. Then, dynamic impact testing with hammer was utilized in most of the nodes of the structure and by using a spectrum analyzer the frequency response functions (FRFs) were obtained. Furthermore, by the use of experimental modal analysis of measured FRFs, the natural frequencies of the structure were identified and compared with those of the analytical models of the structure

Keywords:

dynamic identification , experimental modal analysis , dynamic testing frequency response function