Thermal shape change of some CFRP-aluminum honeycomb sandwiched structures

Carbon fiber reinforced plastic (CFRP) is a suitable material for space and ground-based telescope structures. CFRP has a high stiffness-over-weight ratio and a low thermal expansion coefficient. Together with aluminum honeycomb, CFRP can form very strong light-weight sandwiched structures. These sandwiched structures, which can support high bending moments and shear forces without much deformation, are used widely in the existing and future large-space or ground-based telescopes. However, some special CFRP-aluminum honeycomb sandwiched structures have shape change problems when the absolute temperature changes. In this paper, some of these thermal shape changes are discussed. The designers of the future large telescopes should be fully aware of the shape change problem of these structures.