A study of three dimensional tape spring folds for space applications

One of the most significant drivers in satellite design is the minimisation of mass to reduce the large costs involved in the launch. With technological advances across many fields it is now widely known that very low mass satellites can perform a wide variety of missions. However, the satellite power requirement does not reduce linearly with mass, creating the need for efficient and reliable small satellite deployable structures. One possible structural solution for this application is tape springs. Previous work on tape spring hinges has focused on two-dimensional folds, however applications exist that in- corporate three-dimensional tape spring folds. The present work investigates the static and dynamic properties of three dimensional tape spring folds using both experimental and theoretical methods. The dissertation begins by describing the design and devel- opment of an experimental test rig which was used extensively to analyse the tapes in various configurations. Two dimensional tape spring folds have been initially investi- gated to assess the accuracy of the rig and previously developed theoretical methods. The general properties of three dimensional tape spring folds are then studied before analytical models are applied to the three dimensional problem. The analytical models are derived in two stages. The first studies the three-dimensional problem in a single plane defined in the dissertation as the 'theoretical plane'. The second stage, based on the conclusions of the previous analysis, creates an analytical method that calculates the opening moment of a tape spring mounted at a skew angle to the fold line. The predictions of the mathematical model are then verified against the experimental results. Finally the analytical approach is applied to a theoretical array to perform some initial studies into the deployment dynamics of the system and therefore determine the impact of skew mounted tape springs.