Myung Cho
Chun C. Li, Woon-Yin Wong, Randy Cuberly
Il K. Moon
Gemini 8m Telescopes Project, 950 N. Cherry Ave., Tucson AZ 85719
National Optical Astronomy Observatory, 950 N. Cherry Ave., Tucson AZ 85719
Civil Engineering and Engineering Mechanics, University of Arizona, Tucson AZ 85719
The internal support structure of the Gemini Near Infrared Spectrograph (GNIRS) comprises a series of substructures (modules) which are interconnected to support the optical components and their mechanisms. A very stable support structure is required in the GNIRS to exploit the high image quality of the Gemini telescope. The initial concept for the structure used triangular trusses connecting stiff circular rings; this type of structure did not provide sufficient stiffness. This concept was replaced by a novel type of structure employing lightweight cylindrical modules, with each module produced by numerically controlled machining from a solid. Finite element analysis is combined with three-dimensional layout techniques to develop an optimized structural configuration for each module. A parametric process was performed for the design optimization to produce the highest fundamental frequency for a given weight, as well as to deal with the normal concerns about global deformation and stress.
Appears in Proc. SPIE 3354, "Infrared Astronomical Instrumentation".
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