| The proper assessing and understanding of elastic and inelastic dynamic response of non-structural components; commonly referred to as Secondary systems (S-systems), continues to attract substantial research attention until this very day. This research interest in S-system dynamic response is justified by the fact that in many instances the lion's share of the project's budget is invested in S-systems as opposed to the main structure, referred to as the Primary system (P-system). Although the majority of P-systems, which support the S-systems can be categorized as statically or dynamically coupled structures, much of the research work until recently was concerned with the oversimplified elastic and inelastic response of the two degree of freedom Primary Secondary system (PS-system). Much of the previous research mostly neglected spatial effects on the elastic response, as well as the inelastic response of the nonlinear time variant PS-system. Additionally previous research addressing the inelastic response of PS-systems primarily concentrated on a particular class of bilinearly responding PS-systems. More complex yet likely forms of inelastic response had mostly been ignored. These more complex inelastic response types involve spatial stiffness and strength degradation as well as pinching or slip that may occur in the supporting structural elements of either or both subsystems simultaneously. Moreover, whereas a wealth of numerical research exists on the elastic response of simplified PS-systems, there is little experimental work performed and/or used to verify the various techniques previously developed to quantify the elastic and inelastic dynamic response of PS-systems. In particular, to the author's best knowledge, no experimental work was found addressing the problem of inelastically responding torsionally coupled PS-systems under seismic sequence excitation, which can represent a significant problem for critical structures such as power generation plants.;Realizing the current deficiency, a dual experimental and numerical research program was tailored and performed to provide greater insight into the elastic and inelastic dynamic response of torsionally coupled PS-system. In the course of this research work, the capability of the modified Bouc-Wen-Baber-Noori model (BWBN model) was further extended to encompass spatial pinching using the Generilized Spatial Pinching Function (GSPF). The extended model's capabilities were verified against dynamic and quazi-static experimental data. |
