Uncertainty bounds estimation when simulating vibration response under aeroacoustic loading

Abstract

The simulation of linear vibration response under aeroacoustic loading, involves the aeroacoustic loading spectrum and its spatial distribution, and the modal dynamics of the loaded structure. In most practical applications, this problem can only be addressed statistically because the aeroacoustic loading is temporally random and only partially space-correlated, requiring a time-averaged and space-averaged cross-spectrum description of both the loading and the structure vibration response. However, it is equally common that the spectrum and spatial correlation of the loading is uncertain and—particularly at higher frequencies or higher modal densities—even the modal dynamics of the structure are uncertain (e.g., due to uncertainties in the as-built boundary conditions). This paper will explore what is required to predict the statistical variance and the maximum expected vibration response—in addition to the space-time average cross spectrum—given uncertainty in the modeling parameters.