A Novel Actuated Composite Tape-Spring for Deployable Structures

Abstract

This paper presents a novel composite tape-spring that is suitable for use as a structural element of deployable space structures. The tape-spring uses a combination of material orthotropy and prestress to achieve the unique property known as neutral stability. A consequence of this property is that the tape-springs can be partially rolled and they neither want to unroll or rollup. Previously investigated composite tape-springs always proceed towards their manufactured geometry once the rolling process has been started. This paper documents a procedure to fabricate neutrally stable tape-springs. An analysis methodology is presented that predicts neutral stability in appropriately prestressed laminates. The analysis predictions are shown to agree with observations. Finally, the ability of neutrally stable tape-springs to undergo large elastic deformations with diminishingly small forces is exploited in the development of actuated tape-springs.

Concepts for morphing airfoil sections using bi-stable laminated composite structures

“…Bi-stable and multi-stable structures are currently used for deployable space structure applications [17][18][19][20][21]. A morphing concept [1] was proposed based on bi-stable composites actuated by devices such as piezoceramic or shape memory alloy actuators.…”

CubeSat Deployable Antenna Using Bistable Composite Tape-Springs

“…A consequence of this neutral stability is that diminishingly small forces are required to roll or unroll the tape-spring. According to Murphey [10], [11], such actuated NEM tape-springs offer four prominent features for deployable space structures. First, they allow controlled deployment.…”

Deployable antennas for CubeSat and space communications

“…Several mechanisms have been proposed by several structural engineers; however in this paper we merge the structural engineering aspect with the antenna design concept. A novel composite tape-spring that is suitable for use as a structural element of deployable space structures is introduced in [4][5]. The tape-spring has the unique property that it is neutrally stable.…”