Session: 02-03-03: Dynamic Loads, Wave Propagations, Response, Vibration, Control, and Alleviation of Aerospace Structures and Vehicles

Paper Number: 160841

160841 - Acoustic Vibration Study for Ga-500 Spacecraft Design 

For low-cost space missions with a class C or D risk profile, significant cost and schedule savings can be realized by reducing the amount of analysis and testing performed during development.  For compact, lightweight space vehicles such as the GA-500 spacecraft, one of the most significant savings can be realized by tailoring out vibroacoustic testing in favor of random vibration testing.  This is due in part because GA has in-house capabilities for conducting a random vibration test on an electrodynamic shaker table, but does not have the equipment or expertise to conduct a reverberant chamber or direct effect acoustic test.  

There are provisions in environmental testing documents such as NASA GEVS and SMC-S-016 for foregoing an acoustic test and analysis for small, compact rideshare vehicles given certain criteria are met.  The GA-500 spacecraft is larger than the guidance allows, so an in-depth analytical comparison of the spacecraft dynamic response to the random vibration and vibroacoustic environments is required.  

This technical presentation provides some background on the source of vibration loads, the structural response of the space vehicle, and an overview of how random vibration and acoustic vibration are analyzed and tested.  Then, an example is given on how to compare the analytical responses from random vibration and acoustic vibration to determine which is more critical for each component on the space vehicle.  The conclusion is that even though the GA-500 spacecraft is larger than the exception criteria in NASA GEVS and SMC-S-016, a base-drive random vibration test at the prescribed Protoqualification levels is an adequate test of the structure and there is low program risk associated with foregoing an acoustic test.   

Presenting Author: Matthew Byars General Atomics Electromagnetic Systems

Presenting Author Biography: Matthew Byars is the lead structural analysis engineer at General Atomics - Space Systems Division. He earned a bachelor’s degree in mechanical engineering from the University of Nebraska – Lincoln in 2005 and a master’s degree in mechanical engineering from Kansas State University in 2010. Matt has worked as a structural analyst at Boeing, Spirit AeroSystems, Airbus, Textron Aviation, Sierra Nevada Corporation, Redwire, and General Atomics and is a registered Professional Engineer in the state of Colorado.