Abstract:
Modelling and monitoring tools appropriate for the resin transfer moulding composites
manufacturing route were developed in this study. A simulation of the curing stage of
the process based on a finite elements solution of the non-linear heat conduction
equation was implemented. The simulation involved appropriate submodels for the
incorporation of thermal properties and cure kinetics. A novel non-parametric procedure
which utilises interpolation applied directly to experimental Winefics data proved
adequate for the simulation of chemical and structural phenomena occurring during the
cure. The application of the heat transfer model was successful, the magnitude of
thermal gradients was shown*to be significant and the character of degree of cure
gradients temporary. An inversion of the heat transfer simulation based on genetic
algorithms enabled an optihisation of the cure process parameters to be performed.
The heat transfer simulation was combined with thermal monitoring results in order to
achieve an extension of the local temperature measurements to the whole component.
This combined scheme reproduced successfully the' temperature and degree of cure
distributions. The same approach was implemented with similar outcomes using artificial
cure monitoring results.
Impedance cure monitoring was used in order to follow in real time the reaction
progress. An interpretation was found for the manifestation of vitrification in the
impedance signals. A new equivalent circuit representing accurately the behaviour of the
resin system investigated was developed. A methodology which correlates the progress
of cure with the imaginary impedance spectrum evolution was established.
Dielectric flow monitoring techniques appropriate for the filling stage of resin transfer
moulding were devised. Lineal sensors enabled monitoring of the progress of filling to be
made in both conductive and non-conductive reinforcements.
