This paper discusses the deformation properties of the solar sail IKAROS membrane to identify the possible causes of the phenomena observed by the flight data: mechanics of higher out-of-plane stiffness of the IKAROS membrane. Two possible causes are hypothesized in this paper; the bending stiffness increased by the curvature of thin-film solar cells, and the deformation mode changed by the curvature. Although the second moment of area of the sail membrane is calculated by the natural vibration analyses, the effects of the bending stiffness increased by the curvature on the out-of-plane displacement is small. The effects of the deformation mode on the out-of-plane displacement is examined by geometrically calculating the relationships between the sensitivity of the margin in a circumferential length to the displacement. The results indicate that the sensitivity becomes small as the curvature becomes large. Thus, the high out-of-plane stiffness of the IKAROS membrane can be induced by the increased bending stiffness and by the changed deformation mode due to the curvature of the solar cells.
展开▼
