Prediction of Upper Tolerance Limit of Acceleration Power Spectrum Density of Satellite Panel under Diffused Acoustic Field Excitation

Abstract

Severe vibroacoustic random vibration is easily induced to satellite structure during the flight. Design specification of acoustically induced random vibration for satellite and equipment component is based on the acceleration power spectral density (PSD) at the mount interface. Ground acoustic test is conducted to verify the structural design and abnormal function of equipments. The response of a satellite structure under acoustic test can be predicted by Statistical Energy Analysis. In addition to the mean energy vibration level obtained by SEA, upper tolerance limit of vibration response in PSD needs to be predicted for conservative design purposes. This paper deals with the upper tolerance limit of PSD acceleration level of a satellite plate under high frequency diffused acoustic excitation. The upper tolerance limit is derived based on the statistical distribution of the vibroacoustic response together with the theoretical description of response variance. The upper tolerance limit for the acceleration PSD level obtained by Statistical Energy Analysis is compared with the experiment result. The result from the comparison shows that the upper tolerance limit presented in this paper yields good estimate of PSD upper tolerance level for conservative design. The effect of PSD estimation error in experiment on variance is also discussed.