The non-stationary cross-correlation coefficients in the seismic analysis of MDOF structural systems

A method concerning the evaluation, in a very compact form, of the non-stationary modal cross-correlation coefficients of MDOF structural systems subjected to seismic excitations is presented. It is available both in the case when the excitation is considered as a white-noise process and when it is considered as a filtered process. The evaluation of these coefficients is required when a transient seismic analysis is performed by the use of the modal response spectrum approach. This is necessary when the strong-motion phase of the earthquake is significantly short with respect to the fundamental period of the structure. Copyright (C) 2003 John Wiley Sons, Ltd.