(Un)folding the membrane in the deployable demonstrator of contex-t

Abstract

The paper presents a system, made out of foldable ‘kinked’ beams and a membrane skin, based on a concept referring to origami. The anticlastic curvature of the membrane is obtained by transforming flat triangular parts into space. The following research question is considered: can the foldable system be stable in intermediate configurations? To obtain a well-tensioned membrane in the intermediate positions, the belts connecting the membrane to the frame can be released or increased in tension. A full scale ‘demonstrator’ has been built within the frame of IP-project Contex-T8. Although the deployment - rotating the ‘kinked’ beams about the central axis - was feasible, the tensioning and structural behaviour of the membrane, attached in the nodes of the frame, was not yet thoroughly examined. For that reason one single unit has been analysed. Forces and deformations in the membrane are verified for different opening angles using integrated models including the membrane, connecting belts and ‘kinked’ beams (for the frame). The results of the experimental investigations and numerical models are compared and occurring discrepancies are clarified.