Engineering topics
Publications and source records attributed to Levine-West, M..
The proposed numerical techniques are briefly described and compared to existing algorithms. Their accuracy and robustness are demonstrated through numerical tests with models from ongoing NASA missions.
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Existing and new mode shape expansion methods are presented within the framework of least squares minimization techniques with quadratic inequality constraints.
Several methods for mode shape expansion are investigated. Dynamic equations of motions are used to obtain direct solutions to the expanded eigenvectors.
The high degree of manufacturing precision required in space structures may make them moresusceptible to mode localization. In this demonstration, the mode localization phenomenon isinvestigated using an existing full scale antenna-like structure having the complexity, manufacturingprecision, and dynamic characteristics of space structures. The actual imperfections were measuredand incorporated in a numerical model of the structure. The impact of several parameters thatprovoke the phenomenon were first studied by numerical simulations, then experimentally. Theresults show excellent agreement, thereby confirming the importance of mode localization in thedesign of actual space structure.
The JPL Micro-Precision Interferometer (MPI) is a testbed for studying the use of control-structure interaction technology in the design of space-based interferometers. A layered control architecture will be employed to regulate the interferometer optical system to tolerances in the nanometer range. An important aspect of designing and implementing the control schemes for such a system is the need for high fidelity, test-verified analytical structural models. This paper focuses on one aspect of the effort to produce such a model for the MPI structure, test-analysis model reconciliation. Pretest analysis, modal testing, and model refinement results are summarized for a series of tests at both the component and full system levels.