Investigations on Size Effects of Zerodur®
Abstract
Zerodur® is a well-known glass-ceramic used for optical components because of its unequalled stability under thermal environment (due to its extremely low Coefficient of Thermal Expansion). In particular it has been used since decades in Thales Alenia Space's optical payloads for space telescopes, especially for primary mirrors.The drawback of Zerodur® however is its quite low strength: 10 MPa is historically used as a rule of thumb. However, as performance of space telescopes is increasing, an optimization of the design is necessary and therefore an increase of the strength limit taken into account in the calculations.Thales Alenia Space is therefore currently investigating the so-called "size effect" on Zerodur® (see Weibull theory), under CNES funding, with the aim of re- estimating the lower bound of Zerodur® strength.For this, a complete test campaign has been defined with a high number of samples in order to reduce uncertainties. This article presents the first results obtained.
- Publication:
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13th European Conference on Spacecraft Structures, Materials & Environmental Testing
- Pub Date:
- June 2014
- Bibcode:
- 2014ESASP.727E..77B