1 November 1990 Moisture-induced dimensional changes in hydrophobic graphite-resin laminates
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We have conducted a series of measurements to evaluate the dimensional stability of carbon fiber-plastic laminates based on a new Lockheed-developed hydrophobic resin system. The test specimen was 10 inches long and was in the form of a hollow truncated right circular cone. To aid the metrology the tube was fitted with stainless steel end flanges that were lapped to be flat and parallel to within 0. 0001 in. The design of the fabric lay-up of the tube was chosen to maximize the sensitivity of the test specimen to length changes induced by varying the moisture content of the laminate. A second test specimen prepared with an epoxy resin system was included in the measurement program as a control. The absolute length of each specimen was periodically measured with respect to laboratory grade gage blocks using a digital electronic height comparator. Moisture content changes were induced by exposing the specimens either to a high humidity environment (90 R. H. 1OO F) or to a vacuum over (iO torr 1500 F). Maximum length differences observed in the control sample were of the order of e51 0. 003 in while those in the hydrophobic sample were of order 51 0. 0002 in more than an order of magnitude smaller. The Lockheed hydrophobic resin system shows great promise as a structural material for lightweight telescope tubes optical benches and other structures requiring a high
© (1990) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Marilyn E. Bruner, Marilyn E. Bruner, E. Bahnsen, E. Bahnsen, Thomas Cruz, Thomas Cruz, L. Hong, L. Hong, Bruce K. Jurcevich, Bruce K. Jurcevich, } "Moisture-induced dimensional changes in hydrophobic graphite-resin laminates", Proc. SPIE 1335, Dimensional Stability, (1 November 1990); doi: 10.1117/12.22884; https://doi.org/10.1117/12.22884


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