Abstract
Payloads are exposed to severe vibro-acoustic environments during a rocket launch. At the same time, fill effect happens in narrow room between rocket faring and spacecraft panels. It makes sound pressure level (SPL) increased approximately 10 dB and makes eigen value of spacecraft panel shifted to coupling mode one. The authors analyze the correlation between fill effect and the eigen value shift with using structure and acoustic coupling model. By considering safety design, they show that the modal-interaction model is going to predict much quantity of eigen value shift than existing model one.