David A. Kienholz
CSA Engineering, Inc.
Palo Alto, CA
12th Int'l Modal Analysis Conference, Honolulu, Hawaii, Jan. 31-Feb. 3, 1994
ABSTRACT
A multipoint suspension system is described for supporting test articles such that their unconstrained modal properties will not be altered by stiffness, inertia, or friction forces from the suspension. Intended primarily for flexible space structures, it is suitable for test items with natural frequencies as low as one Hz. Using a combination of passive pneumatic and active electromagnetic subsystems, the suspension offers a wide payload range, near-zero stiffness, zero static deflection, small added mass, and zero friction. The electromagnetic system can also provide active cancellation of added mass, accurate ride-height control, and controlled disturbance input. The concept and hardware are described, test results are given, and applications experience from several installations is discussed. Current development efforts are described, aimed at testing of payloads such as solar arrays and large beam-pointing experiments.