Shape memory polymer composite and its application for deployable space truss

Shape memory polymer composite (SMPC) materials are ideal for space applications due to their unique advantages such as variable modulus, large recovery rate and force, high stability and reliability, etc. A temperature-sensitive SMPC-based deployable structure could be heated and formed into a small volume for launching, and deploys by heating to be above the glass transition temperature Tg. Such characteristics allow for space based structures to become larger and lighter than structures currently used in space. This paper presents some results obtained in the study of SMPC-based materials and structures, including the investigation of classical micro-structural elastic buckling (micro-buckling) and shape memory effects in a rod, the development and testing of a deployable truss structure. Firstly, a type of temperature-sensitive SMPC is prepared with a shape memory polymer (SMP) matrix and carbon fibers. Secondly, its high strain capability and shape memory effects are investigated, and the results suggested that SMPC generates micro-buckling under bending deformation, which can increase the capacity to undergo compressive strains. Thirdly, the truss joints are fabricated using the obtained SMPC, and a truss is constructed using carbon fiber reinforced plastic (CFRP) hollow rods and the developed joints. The truss is then tested and the results indicate the truss has the capability to be stowed into a small volume and deploy to its original shape with a high recovery rate.