Equivalence analysis of acoustic excitation and random vibration exerted on spacecraft units

Abstract

At the unit level test, the small area-to-mass ratio unit of spacecraft generally adopts the random vibration test to simulate the acoustic environment during the launch event. Acoustic excitation and random vibration exerted on spacecraft units reflect different dynamic characteristics. Thus, the equivalence analysis between them deserves to be conducted. In this work, a thruster outside the spacecraft was taken as an example, for it directly experiences acoustic load compared with the electronic equipment inside. The vibroacoustic and random vibration models of the thruster were established, and response behavior was explored. Results show that there are differences in the response distribution rules of acoustic load and random vibration on the thruster. The farther to the thruster root is, the harder acoustic vibration responses can be covered by the random response, so an appropriate safety margin shall be reserved when formulating random vibration conditions of units.