Seismic analysis of secondary systems with multiple supports

An analytical formulation for seismic analysis of multiple connected secondary systems is presented. The formulation leads to the development of a new response spectrum aproach for the analysis of secondary systems. The seismic input in this approach is required to be defined in terms of auto and cross pseudo-acceleration and relative velocity floor response spectra. The cross spectra comprise of the coincident and quadrature spectra for pseudo-acceleration and relative velocity response of an oscillator. By the analysis of the supporting primary structure, these auto and cross spectra can be directly obtained from the ground response spectra. An effective use of these spectra for the calculation of secondary system response is demonstrated by a numerical example. (Author)