STOCHASTIC RESPONSE OF STRUCTURES WITH UNCERTAIN-BUT-BOUNDED PARAMETERS

The uncertainty plays an important role in structural engineering. It is largely recognized that the uncertainty may affect both external excitations and structural parameters. However, while the numerous available data permit to model with good accuracy the excitations as stochastic processes, unfortunately the data about the structural parameters are quite limited. It follows that the probabilistic approach cannot be realistically applied to represent structural uncertainties; indeed, it requires a wealth of data, often unavailable, to define the probability distribution density of the fluctuating structural parameters. Non probabilistic approaches can be alternatively used to treat these uncertainties. In this framework, the interval model seems today the most suitable analytical tool. The aim of this paper is to evaluate the range of the random response of linear structural systems, with slight variation of the uncertain-but-bounded parameters, subjected to stochastic Gaussian excitations by applying the so-called interval perturbation method.