Modal Identification of a Deployable Space Truss.

This paper summarizes work performed under a collaborative research effort between NASA and the German Aerospace Research Establishment (DLR, Deutsche Forschungsanstalt fuer Luft- und Raumfahrt). The objective is to develop and demonstrate advanced technology for system identification of future large space structures. Recent experiences using the Eigensystem Realization Algorithm (ERA) for modal identification of Mini-Mast are reported. Mini-Mast is a 20-meter long deployable space truss used for structural dynamics and active vibration-control research at the NASA Langley Research Center. Due to nonlinearities and numerous local modes, modal idenfification of Mini-Mast proved to be surprisingly difficult. Methods available with ERA for obtaining detailed, high-confidence results are illustrated