The Unroutinary Loads on the LBT Adaptive Secondary MirrorC. Del Vecchio
INAF-OAA, Firenze, Italy
The thin shell of the LBT Adaptive Secondary Mirror has been manufactured, optically polished, and delivered. The operations and tests required before finally mounting it on the telescope have to be run very carefully, as they imply loads completely different from the ones of the adaptive operational modes - studied in the past with very encouraging results.
Deformations and stresses that occur in the lab test runs and operations and in the case of accidental loads require an accurate computation, in order to evaluate a possible exceeding of the material stress limit.
This paper faces the computation method of the stress analysis of some non-routine load conditions that may cause relevant deformations and stresses. After the analysis of the stresses induced in the shell when handling the mirror, the stresses caused by silvering its surface when sitting in the lab support frame have been computed.