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Cratering in glasses impacted by debris or micrometeorites
| Content Provider | NASA Technical Reports Server (NTRS) |
|---|---|
| Author | Kinser, Donald L. Wiedlocher, David E. |
| Copyright Year | 1993 |
| Description | Mechanical strength measurements on five glasses and one glass-ceramic exposed on LDEF revealed no damage exceeding experimental limits of error. The measurement technique subjected less than 5 percent of the sample surface area to stresses above 90 percent of the failure strength. Seven micrometeorite or space debris impacts occurred at locations which were not in that portion of the sample subjected to greater than 90 percent of the applied stress. As a result of this, the impact events on the sample were not detected in the mechanical strength measurements. The physical form and structure of the impact sites was carefully examined to determine the influence of those events upon stress concentration associated with the impact and the resulting mechanical strength. The size of the impact site, insofar as it determines flaw size for fracture purposes, was examined. Surface topography of the impacts reveals that six of the seven sites display impact melting. The classical melt crater structure is surrounded by a zone of fractured glass. Residual stresses arising from shock compression and from cooling of the fused zone cannot be included in the fracture mechanics analyses based on simple flaw size measurements. Strategies for refining estimates of mechanical strength degradation by impact events are presented. |
| File Size | 684748 |
| Page Count | 12 |
| File Format | |
| Alternate Webpage(s) | http://archive.org/details/NASA_NTRS_Archive_19930020179 |
| Archival Resource Key | ark:/13960/t49p7zp6p |
| Language | English |
| Publisher Date | 1993-04-01 |
| Access Restriction | Open |
| Subject Keyword | Nonmetallic Materials Stress Concentration Mechanical Measurement Micrometeorites Fracture Mechanics Space Debris Meteorite Craters Glass Hypervelocity Impact Impact Melts Meteorite Collisions Cratering Topography Shock Loads Long Duration Exposure Facility Fracturing Residual Stress Impact Damage Ntrs Nasa Technical Reports Server (ntrs) Nasa Technical Reports Server Aerodynamics Aircraft Aerospace Engineering Aerospace Aeronautic Space Science |
| Content Type | Text |
| Resource Type | Article |
