Dynamic Fatigue of Ultralow-Expansion Glass for Space Mirrors. Reissue A
Abstract
Ultralow-expansion (ULE) glass is one of the primary materials used for space mirrors because its SiO2-TiO2 composition has a very low coefficient of thermal expansion. Several problems with cracking of this material in the Defense Satellite Program (DSP) led to the conclusion that insufficient design information was available to ensure reliability of the mirror structure. Accordingly, the Materials Sciences Laboratory of the The Aerospace Corporation undertook an investigation into the fracture behavior of ULE glass for space mirrors. Dynamic fatigue experiments were performed on two sets of samples (optically polished and lightly ground) to characterize the fracture behavior of this material in a humid environment. As expected, the flaw size distribution affects the expected lifetime at a given stress and failure probability. In addition, it is shown that the polished material is apparently less sensitive to subcritical crack growth than the unpolished glass.
Document Details
- Document Type
- Technical Report
- Publication Date
- Oct 30, 1988
- Accession Number
- ADA205401
Entities
People
- Dana J. Speece
Organizations
- The Aerospace Corporation