Title: Complex flow phenomena in composite processing : experimental evidence and modeling
Date/Time: 18 November 2020/ 13:40 - 14:30
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Abstract: Functional and structural parts, made so far with metals, have been progressively reengineered by replacing metallic materials by discontinuous fibre reinforced polymers and continuous fibre reinforced composites. 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 fiber reinforcement and in the characteristics of the polymers used. Polymer reinforced by low to medium content of discontinuous fibers (LFTs, SMC, BMC…) belongs to the first one. Polymer reinforced by high content of continuous fiber (CFRP) belongs to the second one. However there is no sharp division boundary between both groups, one type of composite changes gradually into the other. Recent studies showed that discontinuous aligned fibers composites have similar mechanical properties than their continuous counterpart. An important characteristic of continuous fibers is that they cannot flow with the polymer, even if the viscosity of the polymer is low. Continuous fiber 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 fiber reinforcement. However recent works showed that hybrid squeeze-bleeding flow types may occur in CFRP. In addition, because of the initial low viscosity, some resins can be combined with medium volume fraction of discontinuous fibres to get a flowable compound. Increasing the amount of discontinuous fibers to a larger content will lead to a situation where squeeze-bleeding flow modes can occur during manufacturing of composite parts. This seminar will illustrate some complex flow mechanisms observed for both continuous and discontinuous composites. Some models will be presented and discussed.
Bio:Christophe Binetruy received a PhD degree in mechanical engineering from the University of Lille (France) in 1996. Then he joined the IMT Lille-Douai (France) in 1996 as Assistant Professor in the Polymer & Composites Department. He received his habilitation in 2002 and got a Professor position at IMT Lille-Douai in 2003. He joined Centrale Nantes (France) in 2011 as Professor of Mechanical Engineering at the Institute of Civil Engineering and Mechanics (GeM – UMR CNRS 6183) since that time. He led the Processes and Mechanics of Materials Group from 2012 to 2018. He holds the FAURECIA Chair on structural composites for automotive applications since 2011. He was a visiting scholar at the University of Delaware in 2001 and at TU Munich in 2011. He has been Vice-President of the European Society for Composite Materials (ESCM) since 2018. He is currently Affiliated Professor in the Department of Mechanical Engineering at the University of Delaware. His research interests are modeling of composite manufacturing processes with multi-scale and multiphysics-based approaches, as well as design for manufacturing based on concurrent engineering approaches.