Instantaneous earthquake input energy and sensitivity in base-isolated building

摘要

The input energy and energy input rate to a base-isolated (BI) building during an earthquake are considerednand formulated in the frequency domain. The frequency-domain approach for computation of input energynand energy input rate has different remarkable advantages compared with the conventional time-domainnapproach. It is demonstrated that the input energy can be of a compact form via the frequency integrationnof the product between the input component (squared Fourier amplitude spectrum of acceleration) and thenstructural model component (so-called energy transfer function). Furthermore, the energy input rate cannalso be of a similar form via the frequency integration of the product between the instantaneous powernspectrum and the energy transfer function. With the help of this compact form, it is shown that the formulationnin the frequency domain is essential for deriving arbitrary-order closed-form sensitivities of the inputnenergy and energy input rate with respect to uncertain stiffness and damping coeffi cients in the BI storey.nThe closed-form sensitivity expressions provide us with information on the most unfavourable variationnof the uncertain parameters that leads to the maximum input energy and input rate. Copyright © 2009 JohnnWiley & Sons, Ltd.