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The engineering purpose of designing resistant structures in seismic areas goes through the modeling of the earthquake ground motion. To design complex earthquake-resistant structures, above all if the structural non-linearities must be considered, dynamic analysis of the response of the structure is highly recommended instead of the response spectrum analysis. Therefore, the need to generate artificial accelerograms for structural design arises. This paper proposes a stochastic procedure that, based on the seismological point-source model, allows to generate artificial accelerograms. Therefore, the artificial accelerogram generated incorporates the "source," "path" and "site" characteristics. For each term of the seismological model, a corresponding best approximating filter transfer function has been given. Therefore, a new quadruple-filter system has been derived. The proposed approach is used to generate various earthquake records that occurred in Italy. The outcomes of the numerical examples demonstrate the suitability of the proposed study. [ABSTRACT FROM AUTHOR]

In this article, a new stochastic approach is proposed for the analysis of structural systems with uncertainties. This novel strategy method combines the probability transformation method, expressed in terms of characteristic function with a probabilistic version of the Taylor expansion. Some notes about the convergence and the accuracy of the proposed method are reported. The results of these notes and several examples here reported evidence an optimum level of accuracy, coupled with great simplicity of application of this approach, even for relatively high levels of uncertainties. Hence, this method can be considered a valuable tool for the solution of stochastic analyses of engineering systems. Several examples are performed to show the capability of the results established. These applications show how the method is a useful technique for engineering analysis. [ABSTRACT FROM AUTHOR]

The dynamic behavior of nonlinear systems driven by parametric normal delta-correlated processes is studied. A modified version of Ito's stochastic differential calculus that contains the Wong-zakai ot Stratonovich correction term is used to characterize the systems'response under stochastic excitations. The results of this approach are found to be consistent with experimental data obtained by means of a Monte Carlo simulation.

A study on the extension of the ordinary Ito moment equation approach is used to criticize another paper on nonlinear systems. Nonlinear systems driven by external and parametric white-noise processes are targetted. The study shows that the original paper did not specify the inclusion of the Wong-Zakai correction in term f(x,t). However, this criticism is invalid, sincethere is no need to add the correction since the Poisson-distributed pulse processes are physically realizable.