Modelling three dimensional, tape spring based, space deployable structures

Deployable structures are required for many satellite operations, to deploy booms for communications or area deployment for power generation, and many sophisticated mechanisms have been developed for these types of structures. However, tape springs, defined as thin metallic strips with an initially curved cross-section, are an attractive structural solution and hinge mechanism for 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 small two-dimensional tape hinges, but they also have the potential to be used in greater numbers to create larger, more geometrically complicated deployable structures. This publication investigates the applicability of using a simplified modelling approach to predict the deployment dynamics of a three dimensional deployable structure that uses a significant quantity of tape springs. This work builds on previous studies which have focused on the analysis of two dimensional tape spring based structures. The configuration being investigated consists of four walls mounted as a square. Each wall has three fold lines allowing the structure to fold down in a concertina style and each fold line is populated by a series of tape spring hinges mounted in pairs. A total number of around 600 individual tape springs elements are used across the 12 fold lines. A computationally efficient method of simulating the three dimensional deployable structure was studied based on a finite element explicit analysis. Equivalent static and dynamic experimental testing on a breadboard structure is presented allowing a direct comparison of the theoretical and experimental data. It was concluded that this simplified analysis approach is capable of modelling the structural dynamics in the deployment direction for three dimensional structural deployments. As a result, the use of this approach could significantly reduce computation time when performing initial design trade-offs.