A Process Sensitivity Study of Composite Compressive Strength

The effects of variations in curing parameters on the compressive strength of graphite/epoxy laminates were studied. The evaluated parameters were cure temperature, time, and pressure. Two specific settings were chosen for each parameter to form a unique processing envelope centered on the manufacturer's recommended cure cycle. Through factor analysis, high compressive strength was noticed with high cure temperature (204'C), low pressure (0.482 MPa), and long cure time (2.5 hours). This result suggests that deviation of cure time and temperature above the manufacturer's suggested cure cycle will still produce quality laminates. On the other hand, deviation below the manufacturer' s cure cycle will result in incomplete cure, which was evident in the experiment. Furthermore, according to the analysis of variance (ANOVA), the only factor that was significant at the 90% confidence level was cure time, while the cure temperature was slightly less significant. Therefore, cure time was the most sensitive to the compressive response. The next important parameters were cure temperature and pressure.