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Element-specific modal formulations for large-displacement multibody dynamics
- Source :
- NASA, Langley Research Center, NASA(DOD Controls-Structures Interaction Technology 1989.
- Publication Year :
- 1989
- Publisher :
- United States: NASA Center for Aerospace Information (CASI), 1989.
-
Abstract
- Large dispacement assumed-mode modeling techniques are examined in the context of multibody elastodynamics. The range of both general and element-specific approaches are studied with the aid of examples involving beams, plates, and shells. For systems undergoing primarily structural bending and twisting with little or no membrane distortion, it is found that fully-linear, element-specific, modal formulations provide the most accurate time history solutions at the least expense. When membrane effects become dominant in structural problems due to loading and boundary conditions, one must naturally resort to a formulation involving a nonlinear stress-strain relationship in addition to nonlinear terms associated with large overall system motion. Such nonlinear models were investigated using assumed modes and found to lead to modal convergence difficulties when standard free-free structural modes are employed. A constrained mode formulation aimed at addressing the convergence problem is proposed.
- Subjects :
- Spacecraft Design, Testing And Performance
Subjects
Details
- Language :
- English
- Database :
- NASA Technical Reports
- Journal :
- NASA, Langley Research Center, NASA(DOD Controls-Structures Interaction Technology 1989
- Publication Type :
- Report
- Accession number :
- edsnas.19900011753
- Document Type :
- Report