Composite structures for a large-optical test bed

Abstract

A T5OJERL1962 graphite epoxy laminate was selected as the primary structural material for an cptical test bed manufactured by Composite Optics, Incorporated (COT) for use by Eastman Kodak's Federal Systems Division to develop the design of lightweight optical systems with dynamic damping and active conirol of multi-segment primary mirrors. The composite structures for this project consist of a 100 inch diameter 12 inch deep Aft Structure Assembly and six 190 inch long round tubes double tapered from a 3.65 inch midspan I.D. to a 0.90 inch I.D. at the ends. A pseudoisotropic .09 inch thick layup was used for the aft structure to provide a low coefficient of thermal expansion and to meet requirements for stiffness and weight. The tubes were made with a ,06 inch thick (O0/±6O0)s laYup for low longitudinal coefficient of thermal expansion (CTh) and high axial stiffness. The aft structure will support a primary mirror consisting of a center segment and six outboard petal segments. The six composite tubes which attach to actuators at the outboard ends of the aft structure will support the secondary mirror for the Ritchey Chretien optical system.