Dynamic analysis of a deployable space structure

Abstract

A mathematical model and a corresponding simulation code have been developed for investigating the freevibration and forced-response behavior of a deployable space structure. Specifically, the structure considered was the NASA Solar Array Flight Experiment configuration (that has undergone testing on a recent Shuttle flight) where the mast was modeled as an Euler beam column and the solar array was modeled as a membrane. The resulting partial differential equations of motion were transformed such that the boundary conditions were time-invariant. Subsequent use of the Galerkin method resulted in an infinite set of second-order differential equations that were truncated and solved for the frequency and forced-response behavior of the coupled structural components. It is demonstrated that accurate results for frequency and mode-shape characteristics can be obtained with only a small number of generalized coordinates and, thus, appears to be a more computationally efficient algorithm than the finite element method for this type of structure. Similarly, the truncated set of equations was numerically integrated to obtain response histories of certain pertinent variables from a packaged structure, through full deployment, to complete retraction.