Shape Memory Alloy-Enabled Expandable Space Habitat—Case Studies for Second CASMART Student Design Challenge

Design and development of innovative material compositions and mechanisms based on shape memory alloys (SMAs) were accomplished as part of the Consortium for the Advancement of Shape Memory Alloy Research and Technology (CASMART) 2nd student design challenge. The challenge consisted of developing an expandable space habitat where the retention and deployment of such structure employs the use of SMAs. Student groups were provided with an initial set of requirements and given an option to design the material or design with the material, within six months. This paper collectively documents the evaluation, alloy selection, fabrication, testing, and implementation processes of three teams, including the tools and information used to successfully design, develop, and implement SMA material systems and habitat technologies. For the mechanism design, students used a combination of superelastic rods and shape memory springs/wires to design collapsible rings to fold and deploy the habitat. Publicly available design tools were used to size the SMA components based on the provided loading scenarios. For the material system development, compositions based on CuAlMn, NiTiFe, NiTi and NiTiSn alloys were explored and designed to satisfy the given set of requirements. Details pertinent to these designs are described in this work, along with lessons learned.