AMT Seminar: From flow within fibrous microstructure to fibrous microstructure in flow

20 maart 2019 15:00 - Locatie: Lecture room J, Faculty of Aerospace Engineering, Kluyverweg 1, Delft - Door: Department of Communication

In the seminar series in aerospace manufacturing technologies, we are presenting invited speakers with selected topics in the field of novel manufacturing technologies. The  upcoming seminar talk will be given by Professor Christophe Binetruy from École Centrale Nantes      

From flow within fibrous microstructure to fibrous microstructure in flow: experimental evidence and modeling

Over the last decades an increasing number of functional and structural parts, made so far with metals, has been progressively reengineered by replacing metallic materials by polymers, chopped fibre reinforced polymers and continuous fibre reinforced composites. The motivation for this substitution may be to save weight or to bring additional functionalities. Polymer composites are usually divided into two groups, advanced (or high performance) composites and engineering composites. They differ principally in the type and length of the reinforcement and in the characteristics of the polymers used. A polymer reinforced by high content of continuous fibres (CFRP) belongs to the first one. A polymer reinforced with low to medium content of chopped (LFTs, SMC, BMC) belongs to the second one. However there is no sharp boundary between both groups, one type of composite changes gradually into the other. An important characteristic of continuous fibres is that they cannot flow with the polymer, even if the viscosity of the polymer is low. Continuous fibre reinforced polymer (CFRP) always involves a fluid flow through the fibrous medium, whether to create a semi-product like a prepreg that will be further processed to make the final part or to directly manufacture a part from dry fibre reinforcement. However recent works showed that hybrid squeeze-bleeding flow types may occur in CFRP [1]. In addition, because of the initial low viscosity, some resins can be combined with medium volume fraction of chopped fibres to get a flowable compound. Increasing the amount of chopped fibres to a larger content will lead to situation where squeeze-bleeding flow modes can occur during manufacturing of composite parts. During this seminar examples of flow within fibrous microstructures and fibrous microstructures in flow will be presented. Models suitable for each type of flow will be reviewed and discussed. A recent model for hybrid squeeze-flow will be presented.

[1] Hautefeuille, A., Comas-Cardona, S., Binetruy, C. (2018). Mechanical signature and full-field measurement of flow-induced large in-plane deformation of fibrous reinforcements in composite processing. Composites Part A: Applied Science and Manufacturing.

Christophe Binetruy is Professor of Mechanical Engineering at Ecole Centrale de Nantes (France) and Head of the Processes and Mechanics of Materials Group at the Institute of Civil Engineering and Mechanics (GeM). He holds the FAURECIA Chair on structural composites for automotive applications. He received his Ph.D. in Mechanical Engineering from the University of Lille (France) in 1996 and his Habilitation from the University of Lille in 2002. He has co-authored over 250 journal and conference proceeding articles. He has graduated more than 30 Ph.D. students. He is member of the editorial board of Composites Part A, International Journal of Material Forming and Journal of Composite and Advanced Materials. His research interests are modeling of composite manufacturing processes with multi-scale and multi-physics based approaches, as well as design for manufacturing based on concurrent engineering approaches.