Design and Experimental Validation of Foldable Tubular Booms
This webpage presents a detailed study of elastically foldable thin-walled tubular booms made of carbon fiber composites. Stored energy deployable structures made of thin-walled composite materials have several advantages over conventional structures with mechanical joints. Their lightness, low cost due to lesser number of components and behavior insensitive to friction are distinctive advantages. Structures based on this approach have already been used in few missions and a range of novel structural architecture that exploits this approach in future missions has been proposed. For example, the three Astro Aerospace Flattenable Foldable Tubes (FFT) were used as the Mars Advanced Radar for Subsurface and Ionosphere Sounding (MARSIS) antenna on the Mars Express spacecraft. DLR's lightweight deployable boom is an example of recent technology developments for future missions.
The deployment schemes that have been considered so far envisage the release of all constraints on folded structure, to allow the structure to dynamically deploy and self-latch. However this behavior needs to be fully understood and optimized as several dynamic effects at the end of the deployment could damage the structure and yet a slow, highly damped deployment may end without ever achieving the fully deployed configuration. Achieving a balance between these effects is challenging, as demonstrated by the large amount of testing and simulation that was required to achieve the successful deployment of the MARSIS booms.
Folding and deployment of these structures involve significant geometric changes that are associated with instabilities, dynamic snaps and extensive contact/sliding between different parts of the structure. Abaqus/Explicit commercial finite element package is used to capture these complex features. Homogenized material properties of woven carbon fiber laminates are obtained through separate Abaqus/Standard analyses.
In general these structures have low moment resistance in any folded configuration. However a structure snaps back to fully deployed configuration with a significantly high peak moment. This leads to a stable structure once it is fully latched. Figure 2 shows a typical moment-angle relationship.
Figure 3 compares the deformed configurations observed during the experiment with snapshots from the finite element simulation. Detailed analysis of quasi-static behavior is presented in Publications 1 and 5.
Dynamic response of the boom can be generally divided into three phases, main deployment, incomplete latching and rotation of the boom beyond the fully deployed configuration and final, small amplitude vibration of the deployed boom. In the case of hinge presented above, the second phase can follow two different paths depending on where how the localized fold forms at the beginning of overshoot. Check two movies comparing the simulated boom motion to experiments for low and overshoot angles. See publication 2 and 8 for more details.
Simulation tools presented above together with failure criterion for woven composite are used to arrive at optimized designs for the geometry of the hinge. The material of the structure is also being optimized, for example by varying the type of fabric, the number of plies and the ply arrangement. See publications 4 and 7 for more details.
We have considered a deployment scheme that requires a 1 m long monolithic boom with two tape-spring hinges, to be folded around a small spacecraft. The boom is rigidly connected to the spacecraft and expected to self-deploy upon release. It is also required to fully latch straight away, without overshooting.
Simulia News Article
This research has been featured in the February /March 2012 issue of 3DS Simulia Community News. Follow this link for a copy of the article (pages 18 & 19).
- Mallikarachchi, H.M.Y.C., and Pellegrino, S. (2014) Design of ultrathin composite self-deployable booms.Journal of Spacecraft and Rockets.
- Mallikarachchi, H.M.Y.C., and Pellegrino, S. (2014). Deployment dynamics of ultrathin composite booms with tape-spring hinges. Journal of Spacecraft and Rockets 51(2): 604-613.
- Mallikarachchi, H. M. Y. C., and Pellegrino, S. (2013). Failure criterion for two-ply plain-weave CFRP laminates. Journal of Composite Materials 47(11): 1357-1375.(pdf)
- Mallikarachchi, H.M.Y.C. and Pellegrino S. (2011), Design and validation of thin-walled composite deployable booms with tape-spring hinges, 52nd AIAA/ASME/ASCE/AHS/ASC Structures, Structural Dynamics, and Materials Conference, 4 â€“ 7 April 2011, Denver, Colorado, AIAA-2011-2019. (pdf)
- Mallikarachchi, H.M.Y.C. and Pellegrino, S. (2011), Quasi-static folding and deployment of ultra-rhin composite tape-spring hinges, Journal of Spacecraft and Rockets, Vol.48 (1), pp. 187-198. (pdf)
- Mallikarachchi, H.M.Y.C. and Pellegrino, S. (2010), Optimized designs of composite booms with integral tape-spring hinges. 51st AIAA/ASME/ASCE/AHS/ASC Structures, Structural Dynamics and Materials Conference, 12-15 April 2010, Orlando, FL, AIAA-2010-2750. (pdf)
- Mallikarachchi, H.M.Y.C. and Pellegrino, S. (2009), Folding and deployment of ultra-thin composite structures. Proceedings of International Scientific Conference on Advanced Lightweight Structures and Reflector Antennas, Institute of Constructions, Special Systems and Engineering Maintenance of the Georgian Technical University, pp. 48-57, 14-16 October 2009, Tbilisi, Georgia. (pdf)
- Mallikarachchi, H.M.Y.C. Pellegrino, S. (2009), Deployment dynamics of composite booms with integral slotted hinges. 50th AIAA/ASME/ASCE/AHS/ASC Structures, Structural Dynamics and Materials Conference. 4-7 May 2009, Palm Springs, CA, AIAA-2009-2631. (pdf)
- Mallikarachchi, H.M.Y.C. and Pellegrino, S. (2008), Simulation of quasi-static folding and deployment of ultra-thin composite structures. 48th AIAA/ASME/ASCE/AHS/ASC Structures, Structural Dynamics and Materials Conference. 7-10 April 2008, Schaumburg, Illinois, AIAA-2008-2053. (pdf)