Predicting the random acoustic response of a complex structure using FEM techniques

Abstract

Spacecraft built at RCA Astro undergo a sequence of environmental tests which include an acoustic test. Its purpose is to demonstrate the ability of the spacecraft and its components to withstand the acoustic vibration environment imposed on it during launch and transonic flight. This paper describes work done to predict the vibration response of the structure and of some critical components to the severe random acoustic excitation. Finite element techniques were used to model two different equipment panels and a typical stowed solar panel of the satellite. Using the STARDYNE structural analysis software package, the structural responses of these models were predicted. The random excitation capabilities of the program were used to excite the models in a way such as to best simulate the physical mechanisms for random acoustic excitation. The corresponding structural responses on the flight spacecraft were then measured during a flight simulation acoustic test in RCA's reverberation test facility. The predicted and measured responses are presented for comparison.