Space Radiation Effects on Graphite-Epoxy Composite Materials
Abstract
The objective of this study is to characterize radiation effects or engineering properties, dimensional stability, and chemistry on state-of-the-art composite systems. This investigation used T300/934 graphite-epoxy composite that was subjected to 1.0 MeV electron radiation for a total dose of 1.0 x 10 to the 10th rads at a rate of 5.0 x 10 to the 7th rads/hour. This simulates a worst-case exposure equivalent to 30 years in space. Mechanical testing was performed on the 4-ply unidirectional laminates over the temperature range of -25O deg F (116K) to +250 deg F (394K). A complete set of in-plane tensile elastic and strength properties were obtained. In addition electron microscopy was used to study and analyze the fracture surfaces of all specimens tested. Results indicate that little difference in properties is noted at room temperature, but significant differences are observed at both low and elevated temperatures. Dynamic-mechanical analysis showed that the glass transition temperature of the epoxy matrix was lowered by over 100 deg F (56K) after being irradiated. Thermomechanical analysis demonstrated that volatile products are produced upon heating the irradiated material. These degradation products were analyzed by infrared spectrophotometry and mass spectrometry, and found to be low molecular weight material produced by polymer chain scission and crosslink breakage. In conclusion, electron radiation acts to produce low molecular weight material in the epoxy resin matrix.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jun 01, 1984
- Accession Number
- ADA305777
Entities
People
- Carl T. Herakovich
- George F. Sykes Jr
- Scott M. Milkovich
Organizations
- Virginia Tech