Structural analysis of a 50 cm diameter open-back triangular cell beryllium mirror in a cryogenic environment

摘要

This paper discusses NASTRAN finite element analysis of the Sub-scale Beryllium Mirror Demonstrator (SBMD), which has been developed by Ball Aerospace as an experimental lightweight (9.76 kg/m~2 areal density) design concept for the Next Generation Space Telescope (NGST). The mirror was repeatedly subjected to a 30 K environment in the large cryogenic test chamber at Marshall Space Flight Center (MSFC). Deformations on the mirror surface were measured optically. The surface distortions predicted by NASTRAN were analyzed for comparison with the measured values. Model results compared more favorably with measured results for the ambient temperature cases. For the cryogenic cases, the influence of geometry and material property variations was investigated to obtain closer correlation.