Permeability enhancement with different glass fiber quasi-UD structure arrangements for RTM-TP process

Abstract : Three different types of a quasi-unidirectional fabric have been produced and studied in order to reach the objective of the enhanced longitudinal permeability. The overall goal of the project TAPAS is to use the optimised fabric in a RTM process adapted to high fluidity polyamide 6,6. Microstructure study is undertaken with Scanning Electron Microscope (SEM) and X-Ray Tomography (X-RT) images as well as image treatment by stereology. Permeability has been measured experimentally and estimated by an analytical model based on Kozeny-Carman relationship and by the inverse identification with the help of the Brinkman equation numerically solved by the Proper Generalized Decomposition method (PGD) and finite elements (FEM). Both models for the prediction of permeability seem to give comparable results, whereas experimental values of permeability are quite higher than model ones. The fact that both models give predictions with the help of 2D cut images should explain this discrepancy with experiments. Nevertheless, the same increasing trend in permeability for the three fabrics is observed both on experimental and analytical model values. Finally, an example of RTM-TP composite plate with PA6,6 and the most permeable fabric among the three, at a volume fraction of 54.2%, is given as a proof of concept. © 2015 International Committee on Composite Materials. All rights reserved.