ISSN:
0272-8397
Keywords:
Chemistry
;
Chemical Engineering
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
Notes:
Samples of 16-ply, quasi-isotropic bismaleimide composites were aged in convection ovens at 150°C, 177°C, and 204°C for up to 16,000 hours. As a measure of degradation, transverse microcrack density was characterized as a function of time, temperature, and ply depth. Times required to reach onset and saturation crack density were delayed on the tool side of the laminate, for lower temperatures, and for deeper ply depths. Saturation crack densities ranged from 35 cracks/cm to 46 cracks/cm, depending on ply depth. Master curves were constructed for each ply level to express all time-temperature data for that ply as a single reference curve. A mass transfer analysis further suggests that diffusion is the controlling mechanism in the degradation process. Finally, a prediction of the degradation behavior in the 120,000-h lifetime of the HSCT aircraft for a sustained temperature of 150°C indicates that ∼13 plies will have reached initiation in a quasi-isotropic laminate.
Additional Material:
12 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/pc.750160609
