Inflatable antenna structures: Deployment analysis of torus bounded Z-fold scalable planar membrane reflector

Abstract

Compact packaging and smooth deployment reliability, lightweight and large operational size are ideal requirements of inflatable space structures. Space inflatable antenna, one of the recent ask, demands post-deployment surface flatness in addition to ideal necessities. The work in this paper employs a novel technique namely collective zig-zag folding for an inflatable torus and planar reflector assembly. This research accomplishes various tasks with a focus on planar inflatable antenna by solving the drawback of surface flatness in an origami packaging approach. The torus-reflector assembly is compactly packed by employing two different crease orientation strategies. Aiming at large-scale structure, the deployment behaviour of inflatable antenna assembly is investigated experimentally and numerically. The in-plane loading of a torus due to inflation pressure is derived, followed by the calculation of force induced on the outer edge of the inflated torus. The quasi-static deployment by varying the inflation pressure from a few up to several hundreds of kPa is solved to determine the inflated shapes and deployment behaviour of a fully-folded structure. Uniform pressure method was used to observe the effect of fold-lines on deployment instability. Force–displacement response gives insight into the wrinkling in the creased planar reflectors. The shape of the inflated assembly is found to be close to experimental models for the same amount of inflation pressure. The wrinkles and overall surface error lie within expected range as depicted from comparison.