Free-free and fixed base modal survey tests of the Space Station Common Module PrototypeThis paper describes the testing aspects and the problems encountered during the free-free and fixed base modal surveys completed on the original Space Station Common Module Prototype (CMP). The CMP is a 40-ft long by 14.5-ft diameter 'waffle-grid' cylinder built by the Boeing Company and housed at the Marshall Space Flight Center (MSFC) near Huntsville, AL. The CMP modal survey tests were conducted at MSFC by the Dynamics Test Branch. The free-free modal survey tests (June '90 to Sept. '90) included interface verification tests (IFVT), often referred to as impedance measurements, mass-additive testing and linearity studies. The fixed base modal survey tests (Feb. '91 to April '91), including linearity studies, were conducted in a fixture designed to constrain the CMP in 7 total degrees-of-freedom at five trunnion interfaces (two primary, two secondary, and the keel). The fixture also incorporated an airbag off-load system designed to alleviate the non-linear effects of friction in the primary and secondary trunnion interfaces. Numerous test configurations were performed with the objective of providing a modal data base for evaluating the various testing methodologies to verify dynamic finite element models used for input to coupled load analysis.
Driskill, T. C. (NASA Marshall Space Flight Center Huntsville, AL, United States)
Anderson, J. B. (NASA Marshall Space Flight Center Huntsville, AL, United States)
Coleman, A. D. (NASA Marshall Space Flight Center Huntsville, AL, United States)
August 16, 2013
January 1, 1992
Publication: In: International Modal Analysis Conference, 10th, San Diego, CA, Feb. 3-7, 1992, Proceedings. Vol. 1 (A94-12476 02-39)