Experimental modal analysis for dynamic models of spacecraft

An unconstrained component-mode synthesis technique based on measured modal data for testing solar-array-type structures is presented. A polynomial approximation for the measured modes is introduced to overcome the difficulty involved in synthesizing such a platelike structure; namely, that rotational displacements cannot be measured in the usual modal test. The examples that are adduced demonstrate that this method has potential as an alternative for modal tests of a complete structure. (P.D.)