Impact of Damping Uncertainty on SEA Model Response Variance

Statistical energy analysis is commonly used to predict high‐frequency vibroacoustic levels. This statistical approach provides the mean response over an ensemble of random subsystems that share the same gross system properties such as density, size, and damping. Recently techniques have been developed to predict the ensemble variance as well as the mean response. However these techniques do not account for uncertainty in the system properties. In the present paper uncertainty in the damping loss factor is propagated through the analysis to obtain more realistic prediction bounds that account for both ensemble and damping variance. The analysis is performed on a stiffened composite cylinder representative of an aircraft fuselage. Realistic bounds on the damping loss factor estimates are determined using measurements acquired on the stiffened composite cylinder in the lab. The analysis demonstrates that uncertainty in system properties, such as damping, should be considered when computing the variance of t...