Analysis of structures with random axial stiffness described by imprecise probability density functions

This paper addresses the analysis of structures with random axial stiffness described by imprecise probability density function (PDF). Uncertainties are modelled as random variables whose PDF is assumed to depend on interval basic parameters (mean-value, variance, etc.). The main purpose of the analysis is to propagate the imprecise PDF of the random axial stiffness by establishing approximate bounds on the mean-value and variance of the response. To this aim, an efficient method is proposed which relies on the combination of standard probabilistic analysis with the so-called improved interval analysis via extra unitary interval and the Rational Series Expansion, recently introduced by the authors. The accuracy of the proposed bounds of response statistics is demonstrated by appropriate comparisons with the results obtained performing standard Monte Carlo Simulation in conjunction with a combinatorial procedure.