Vibration Testing Using Spectra with 20 to 50 Breakpoints

This paper discusses the approach used by engineers at National Technical Systems to perform vibration testing on three Space Shuttle components in 1982 and 1983. All three programs involved sinusoidal, random, and combined sinusoidal/random vibration, with the random vibration in some cases involving high numbers of break-points and some programs requiring applied temperature and/or pressure in addition to the applied vibration. Each test program is briefly summarized in terms of specific requirements, after which the technical difficulties and technical solutions are discussed. Equipment schematics and sample test data in the form of x-y plots are also presented.