Civil Engineering ETDs

Publication Date

2-1-2012

Abstract

The ability to fold and unfold large sensor structures in space using hinges is important for space-based sensor technology. Tape spring hinges have become common in deployable space structures due to simplicity, repeatability and unique folding properties. The mechanical response of these hinges (moment-curvature, energy stored etc.) is important in ensuring safety, deployment accuracy as well as optimizing cost of the structure. In an effort to learn more about the folding and deployment properties, finite element software, Abaqus\u2122, was used to analyze a hinge using multidirectional bending. The analysis involved large deformation (rotation through 180 degrees), nonlinear geometric loading. In order to increase confidence in the analysis procedures, a study was conducted on how the type and size of elements affects stability and buckling of a simply-supported plate. In order to fold a tape spring, a specified length of the middle segment of the hinge was first flattened, so the initial curvature about the long axis of the hinge was removed. This minimizes the moment of inertia and hence stiffness allowing it to be folded. With the middle segment flattened, the hinge was subjected to opposite-sense bending about the hinges short axis (axis perpendicular to the length of the tape spring). In addition to providing the needed mechanical response, the study allowed investigation into the optimum method of folding a hinge. Energy stored during folding and unfolding could be evaluated which allows the designer to determine adequate passive damping to obtain necessary post-deployment stability and pointing accuracy.'

Keywords

Expandable space structures--Computer simulation, Expandable space structures--Design and construction, Hinges--Design and construction, Numerical analysis.

Document Type

Thesis

Language

English

Degree Name

Civil Engineering

Level of Degree

Masters

Department Name

Civil Engineering

First Committee Member (Chair)

Ng, Percy

Second Committee Member

Ghosh, Ashok K

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