| 1. |
- Wei, Jianzheng, et al.
(författare)
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Design and testing of inflatable gravity-gradient booms in space
- 2020
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Ingår i: CEAS Space Journal. - : SPRINGER WIEN. - 1868-2502 .- 1868-2510. ; 12:1, s. 33-41
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Tidskriftsartikel (refereegranskat)abstract
- Inflatable space structures have many advantages such as small size, high reliability, and low cost. Aiming at a gravity-gradient boom for an XY-1 satellite, New Technology Verifying Satellite-1, a slender inflatable boom with low magnetic is presented. First of all, an inflatable boom with six self-supporting thin shells made of carbon and Vectran fiber composite materials on the inner wall was designed for eliminating a magnetic dipole moment and increasing structural stiffness. A precise stowage was designed for a tip mass surrounded by a pair of lightweight honeycomb blocks added on the top of the boom. The stowed boom was tested by sine sweep vibrations with three directions on the ground to verify the reasonable design. The XY-1 satellite which carried the inflatable boom was launched into low orbit. After being stowed state in space for at least 6 months, the inflatable boom orderly unfolded a 2.0 kg tip mass to 3.0 m away in May, 2013. The inflatable boom was successfully deployed from a series of photographs received on the satellite. The results show that this kind of lightweight inflatable boom with self-supporting thin shells can orderly unfold and fulfil the function of gravity-gradient in space for a long time.
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| 2. |
- Wei, Jianzheng, et al.
(författare)
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Modal analysis and identification of deployable membrane structures
- 2018
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Ingår i: Acta Astronautica. - : Elsevier. - 0094-5765 .- 1879-2030. ; 152, s. 811-822
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Tidskriftsartikel (refereegranskat)abstract
- The development of ultra-lightweight sails presents many challenges due to their large size and extreme flexibility. One of their key technologies is the design of deployable booms, in particular how to deploy and support the membrane structure. In this paper, a deployable sail with four triangular membranes supported by inflated booms enhanced by four self-supporting thin shells inside and Velcro outside is presented. The feasibility of the folding and unfolding processes is demonstrated, and their modal properties investigated. Firstly, the pressure variation and acceleration time history of a single boom during unfolding process were obtained by dynamic testing system, a finite element model of boom was proposed and structural natural frequencies by simulation were validated by experimental testing. Further, an 8.0 x 8.0 m(2) prototype was assembled and stowed in a Phi 700 mm by 300 mm container, and the structure was fully deployed with gas control. A finite element model of a combination of inflatable booms and triangular membranes was used to predict the structural overall bending modes. The effect of membrane wrinkling was simulated and controlled to improve membrane precision. This work validated the concept of deployable membrane structural design. The proposed finite element models were verified by experimental testing to be useful for membrane structure analysis.
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| 3. |
- Wei, Jianzheng, et al.
(författare)
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Quasi-static folding and deployment of rigidizable inflatable beams
- 2021
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Ingår i: International Journal of Solids and Structures. - : Elsevier BV. - 0020-7683 .- 1879-2146. ; 232
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Tidskriftsartikel (refereegranskat)abstract
- This paper is concerned with a theoretical and experimental study of the deployment of inflated curved slender beams. A theoretical model for a beam with effects from restoring force and moment on deployment angle is proposed. Assuming slow deployment, a quasi-static viewpoint is utilized to simplify the model which the buckling cross-section is considered. The relation between deployment angle and contact area at the instability bending point is studied for the membrane chamber of a thermally rigidizable inflatable beam. While an inflated beam was constrained as simply-supported and fixed-free at its ends, the relations between the restoring force and moment and the internal pressure and its angle were tested by adding to the mechanical experimental method an infrared thermal imager. Results show that the restoring force and moment are increasing with the pressure at a given angle. Moreover, the restoring moment is nonlinearly related to the deployment angle. The correctness of the theoretical model was verified through experiments.
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