Influence of Quality Control Variables on Failure of Graphite/Epoxy Under Extreme Moisture Conditions
SourceTension tests on (0°)g T300/5208 graphite/epoxy composites were performed to determine the influence of various quality control variables on failure strength as a function of moisture and moderate temperatures. The extremely high- and low-moisture contents investigated were found to have less effect upon properties than did temperature or the quality control variables of specimen flaws and prepreg batch-to-batch variations. In particular, specimen flaws were found to reduce drastically the predicted strength of the composite, whereas specimens from different batches of prepreg displayed differences in strength as a function of temperature and extreme moisture exposure. The findings illustrate the need for careful specimen preparation, studies of flaw sensitivity, and careful quality control in any study of composite materials.