A study of tape spring fold curvature for space deployable structures

Abstract

Tape springs, defined as thin metallic strips with an initially curved cross-section, are an attractive structural solution and hinge mechanism for small satellite deployable structures because of their low mass, low cost, and general simplicity. They have previously been used to deploy booms and array panels in various configurations that incorporate a two-dimensional deployment of the tape. However, applications currently exist that incorporate three-dimensional tape springs folds. To accurately model the deployment of an appendage mounted with tape spring hinges, it is necessary to accurately model the opening moments produced from the material strains in the tape spring fold. These moments are primarily a function of curvature. This publication uses a photographic method to analyse the curvature assumptions of twodimensional tape spring folds and to define the curvature trends for three-dimensional tape spring folds as a basis for calculating the opening moment. It is found that although a variation in the curvature can be seen for three-dimensional tape spring folds, its effect is secondary to the tape thickness tolerance. Therefore, constant curvature models are concluded to be accurate enough for general tape fold applications.

Elasticity and stability of shape-shifting structures

“…Depending on the fiber orientation, the presence of the fiber embedded in the epoxy matrix may give these materials an orthotropic response, thus providing design criteria for the orientation of the stimulus chosen to induce snapping [24]. Such structures may enable morphing components for wind turbines [106], mechanisms for swimming or flying [107], ventricular assist devices [108], and for lightweight, deployable structures [109,110]. In a similar manner, the orientation of the residual stress or prestress resulting from fabrication can alter the geometric criteria for bistability [111,112,113].…”

Approximate analytical solutions of an axially moving spacecraft appendage subjected to tip mass

“…Moreover, a differential equation similar to equation (11) can be derived for the generalised coordinates vector r(t).…”

Importance of structural damping in the dynamic analysis of compliant deployable structures

“…Quasi-static analyses of the folded configuration submitted to end loads were also performed in [9] and correctly predicted thanks to a variational technique. Finally, more complex and compact three dimensional foldings can be obtained and were studied, first analytically in [10], then experimentally in [11,12]. Tape springs can also be combined to form tape spring hinges [13].…”