Reliability Analysis of Structures with Interval Uncertainties under Stochastic Excitations

In this paper, an approach able to evaluate approximate explicit expressions of interval response statistics and structural reliability of randomly excited linear structures with uncertain parameters is addressed. The excitation is modeled as a stationary Gaussian random process. Uncertainty in structural parameters is handled by applying the interval model. Under the assumption of independent up-crossings of a specified threshold, a procedure for the analytical derivation of interval reliability sensitivity is presented. The key idea is to perform stochastic analysis in the frequency domain by applying the improved interval analysis in conjunction with the so-called Interval Rational Series Expansion (IRSE). A wind-excited truss structure with interval stiffness properties is analyzed to show the effectiveness of the proposed procedure.