High intensity acoustics simulated by a shaker

Designing an appropriate shaker random vibration test to accurately simulate a high intensity acoustic environment is complicated by the fundamental differences in the nature of acoustic excitation and baseshake input, as well as test fixture and boundary condition differences. A coupon random vibration test of a spacecraft panel with imbedded heatpipe component was performed to simulate the expected acoustic environment at lift-off and flight. Analytical predictions of the acoustic response of the full panel were made and then compared to predictions of the baseshake response of the coupon configuration at specific locations. An appropriate shaping profile was then designed for the random vibration test. The resulting responses produced by the random vibration test were found to be a good representation of the acoustic responses in both overall response levels and power spectral densities.