Properties of a CFRPC Cured at Staged Cure Cycles

Thermal, rheological, and mechanical properties of a carbon fiber reinforced polymer composite (CFRPC) cured at different one-stage and two-stage cure cycles were studied. The results suggested that an encapsulated sample rheometer (ESR) can be used as an ex-situ cure-monitoring instrument to mimic autoclave/oven curing and, hence, eliminate the need for multiple measurement instruments. Utilizing the ESR as the main ex-situ cure-monitoring instrument makes it possible to offer a new approach to curing composites. In the new approach, called Material State Management (MSM), the acceptance of cure is based on the materials¿ viscoelastic properties as measured by the ESR during cure and post-cure monitoring. Moreover, knowledge of the material¿s viscoelastic properties during cure can be used to improve the current cure specifications. In the MSM approach, cure process confidence limits can be prescribed based on the viscoelastic properties of the material, thus addressing the shortcomings of the current time-temperature approach to curing.