ONLINE CURE MONITORING OF EPOXY GRAPHITE COMPOSITES USING A SCALING ANALYSIS AND A DUAL HEAT-FLUX SENSOR

On-line cure monitoring of an epoxy/graphite composite was studied. A scaling analysis derived the dimensionless Damkohler number for cure monitoring. A dual heat flux sensor was designed from a pile of three thermocouples to provide on-line estimation of thermal diffusivity and to measure change in heat flux for calculating the Damkohler number. Verification of this cure monitoring technique was made using differential scanning calorimetry. A simplified cure model was developed for a commercial epoxy/graphite prepreg. Conventional model-assisted cure cycle design was compared to the on-line monitoring technique.