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Dynamic analysis of space-related linear and non-linear structuresIn order to be cost effective, space structures must be extremely light weight, and subsequently, very flexible structures. The power system for Space Station Freedom is such a structure. Each array consists of a deployable truss mast and a split blanket of photo-voltaic solar collectors. The solar arrays are deployed in orbit, and the blanket is stretched into position as the mast is extended. Geometric stiffness due to the preload make this an interesting non-linear problem. The space station will be subjected to various dynamic loads, during shuttle docking, solar tracking, attitude adjustment, etc. Accurate prediction of the natural frequencies and mode shapes of the space station components, including the solar arrays, is critical for determining the structural adequacy of the components, and for designing a dynamic control system. The process used in developing and verifying the finite element dynamic model of the photo-voltaic arrays is documented. Various problems were identified, such as grounding effects due to geometric stiffness, large displacement effects, and pseudo-stiffness (grounding) due to lack of required rigid body modes. Analysis techniques, such as development of rigorous solutions using continuum mechanics, finite element solution sequence altering, equivalent systems using a curvature basis, Craig-Bampton superelement approach, and modal ordering schemes were utilized. The grounding problems associated with the geometric stiffness are emphasized.
Document ID
19910043989
Acquisition Source
Legacy CDMS
Document Type
Conference Paper
Authors
Bosela, Paul A.
(Cleveland State University OH, United States)
Shaker, Francis J.
(NASA Lewis Research Center Cleveland, OH, United States)
Fertis, Demeter G.
(Akron, University OH, United States)
Date Acquired
August 14, 2013
Publication Date
January 1, 1990
Subject Category
Structural Mechanics
Meeting Information
Meeting: Southeastern Conference on Theoretical and Applied Mechanics
Location: Atlanta, GA
Country: United States
Start Date: March 22, 1990
End Date: March 23, 1990
Accession Number
91A28612
Funding Number(s)
CONTRACT_GRANT: NAG3-1008
Distribution Limits
Public
Copyright
Other

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