Toroidal deployment of morphing cylindrical lattices

Morphing composites are relatively new types of structure that change their shape due to inherent combinations of anisotropy, pre-stress and curvature. They have found use in deployable spacecraft structures, including booms and solar generators. However, little work has been completed on the utilisation of morphing composites in the design of curved space structures, e.g. parabolic dish antennae. This study focuses on the development and testing of a morphing composite cylindrical lattice that deploys along a toroidal (curved) path, which has potential to be used in future deployable antennae. This structure achieves its curved deployment through the tailoring of lattice fastener pitch, where the fasteners are more closely spaced on the inside of the curve and further apart on the outside. A numerical model of this new structure is developed and compared with a straight cylindrical lattice of similar configuration, to determine the effect that curving a lattice has on the stability landscape. The numerical model shows that the curving lattice produces a larger longitudinal curvature during deployment and smaller transverse and twisting curvatures, than the equivalent straight lattice. It also produces a marginally smaller force and extends to a slightly shorter deployed state. This numerical model is verified by comparison with experimental testing, which shows good agreement in key areas of the stability landscape.