Analyses on the deformation mechanisms of fabrics based on rCF staple fibre yarns for thermoset composite applications

• Applicants: Professor Dr.-Ing. Chokri Cherif; Dr. Thomas Gereke
• Subject Area: Lightweight Construction, Textile Technology
• Term: since 2020
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 442070201

Composite constructions provide particular advantages for complex shell-like components produced by an integral construction method. Textile reinforcement structures offer a good balance between the ease of manufacture to produce preforms directly in the shape of final 2D and 3D component and the scope of optimisation for part-specific material properties (unlike isotropic construction materials), for example by aligning fibres precisely in the direction of load. Due to current megatrends in the areas of material efficiency, electro mobility and CO2 reduction as well as the persisting demand for high performance levels, the use of fibre-reinforced polymer composites, especially carbon fibre-reinforced polymers, is steadily increasing in various industries. With the increasing use of carbon fibres (CF), the disposal of CF waste and end-of-life composite parts has become a major concern. Since the production of CF is also extremely energy- and cost-intensive, the recovery of high-quality recycled carbon fibre (rCF) and its introduction into a second life cycle are ecologically and economically reasonable.The research project aims at the numerical-experimental analysis of the deformation mecha-nisms of yarns and fabrics based on staple rCF for thermoset composite applications. For this purpose, profound investigations on the development of yarns with high uniformity and defined mechanical properties from staple rCF, in particular with defined, reproducible force-elongation behaviour, need to be carried out. To achieve this goal, a new approach will be followed in this project by using auxiliary staple fibres with <=10 wt% in order to avoid significant degradation of composite properties. It is emphasised that the yarn to be developed has the highest possible rCF content (at least 90 wt% rCF) to reach maximum mechanical performance. Different yarn structures will be investigated by using wrap and DREF-friction spinning techniques so that the effect of yarn structures because of varying yarn force-elongation behaviour on the drapability of the fabrics can be explored. For the analysis of the structural-mechanical behaviour of staple fibre yarns and textile fabrics, a CAE chain based on parameterised numerical models on different length scales will be con-structed and validated.

• DFG Programme: Research Grants