Time-domain stochastic analysis of structures subjected to spectrum-compatible earthquake excitations

A method for the time-domain stochastic analysis of linear structures subjected to non-stationary in amplitude earthquake excitations is presented. In particular the earthquake is considered to be a filtered process compatible with the response spectra proposed by the Eurocode 8, modulated by an opportune time function. The filter equations, obtained by the authors in another paper, are advantageously utilised for evaluating numerically the evolutionary second order response moments. The analysis of the results related to a simple example has evidenced that these quantities may lead to different results respect to those obtained by considering both the input and output as stationary processes.