Bounds on response variability of stochastic finite element systems: effect of statistical dependence

Abstract

A methodology to evaluate the spectral distribution-free upper bounds of the response variability of stochastic finite element systems characterized by statistical dependence among the stochastic fields of differept finite elements is developed. The structural systems examined consist of linearly elastic frames subjected to static loads. The computation of these bounds is achieved by extending the notion of the variability response function' of a stochastic system to frames analyzed by the finite element method. Until now, the variability response function had only been established for stochastic finite element systems characterized by statistical independence among the stochastic fields of different finite elements. However, the assumption of statistical dependence is more suitable for the analysis of certain structures, like reinforced concrete ones cast in one step. It was concluded that the assumption of statistical dependence produces larger values for the upper bounds of the response variability of the structure, when compared to the corresponding values under the assumption of statistical independence.