Effect of Nonuniformities in Temperature on Resin Flow during the Lamination of Polymer Composites

A method is described for analyzing the effect of nonuniformities in temper ature on the flow of resin during the lamination of B-staged prepreg layers. The nonunifor mities in temperature affect the distribution of the resin viscosity and flow in a complex manner due to the presence of a cross linking reaction which renders the viscosity of the resin dependent on its thermal history. The viscosity distribution and the flow field are determined by evaluating the trajectories or, equivalently, the thermal histories of the fluid elements for a few representative temperature distributions. It is shown that, depending upon the nature of nonuniformity, the magnitude of the resin flow can differ significantly from that evaluated by assuming a uniform temperature distribution in the lamination assembly.