Autoclave Processing for Composite Material Fabrication. 1. An Analysis of Resin Flows and Fiber Compactions for Thin Laminate.

High quality long fiber reinforced composites, such as those used in aerospace and industrial applications are commonly processed in autoclaves. An adequate resin flow model for the entire system laminatebleeder breather, which provides a description of the time-dependent laminate consolidation process, is useful in predicting the loss of resin, heat transfer characteristics, fiber volume fraction and part dimension, etc., under a specified set of processing conditions. This could be accomplished by properly analyzing the flow patterns and pressure profiles inside the laminate during processing. In this paper a newly formulated resin flow model for Composite prepreg lamination process is reported. This model considers viscous resin flows in both directions perpendicular and paraliel to the composite plane. In the horizontal direction, a squeezing flow between two nonporous paral1el plates is analyzed, while in the vertical direction, a poiseuille type pressure flow through porous media is assumed. Proper force and mass balances have been made and solved for the whole system. The effects of fiber-fiber Interactions during lamination are included as well. The unique features of this analysis are 1 the pressure qradient inside the laminate is assumed to be generated from squeezing action between two adjacent approaching fiber layers, and 2 the behavior of fiber bundles is simulated by a Finitely Extendable Nonlinear Elastic FENE spring. Favorable comparisons between model predictions and experimental data available in literature are found. MM