Seismic Behavior and Response Sensitivity of Secondary Structural Systems

Keywords: Primary Secondary System Interaction, Stochastic Sensitivity Analysis, Floor Response Spectrum, Secondary Systems, Seismic Effects, Damping, and Structural Dynamics.

Abstract: In earthquake engineering research, an area of increasing concern is performance of secondary systems which are anchored or attached to primary structures systems. Many secondary systems perform vital functions whose failure during an earthquake could be just as catastrophic as the failure of the primary structure itself. The research is focused on developing a greater understanding of the dynamic behavior of secondary systems under seismic loads. It summarizes: 1) a state-of-the-art review on seismic response of secondary systems; 2) stochastic response sensitivity analysis of secondary systems; 3) the development of an approach for modifying floor response spectra widely used in current design; and 4) response prediction of secondary systems with primary systems exhibiting nonlinear behavior. This report addresses several important issues in seismic design. First, some significant effects of primary-secondary system interaction on secondary system response are investigated following a stochastic sensitivity analysis. These effects include nonclassical damping, primary structural yielding, and primary structural parameter uncertainties. These effects are quantified and then translated into necessary modifications of the floor response spectra when they are used in the design procedure.