Model based prediction of fold development of textile composite reinforcements

由于其突出的密度特异性机械性能，纺织增强复合材料注定是高性能材料的应用。在三维部件的生产中，增强纺织品被形成（覆盖）成接近部件几何形状的预制品。在悬垂过程中，织物的设计和性能、粗纱的种类、纤维的取向和组分的几何形状是决定悬垂效果的因素。此外，外力的大小和方向对褶皱的发生、方向和幅度也有重要的影响。由于粗纱之间的滑动，在剪切变形过程中会出现一些局部锁紧的地方，从而导致织物结构的局部变化及其机械响应。预测织物结构和粗纱类型对织物折叠机理的影响是织物增强复合材料设计的重要目标。然而，今天的模型缺乏灵活性，无法考虑由不同粗纱性能或不同纺织性能引起的多种因素，并将这些信息与折叠机制的预测联系起来。本课题的目的是对纺织复合材料增强材料的锁紧剪切角进行预测。

Due to their outstanding density-specific mechanical properties, textile reinforced composites are predestined for high performance material applications. In the production of three-dimensional components, reinforcing textiles are formed (draped) into preforms close to the component geometry. In the drape process, the textile design and properties, the type of the roving, the fibre orientation and the component geometry are the determining factors. Also, the magnitude and direction of the applied external forces play a significant role in the folding initiation, direction, and the amplitude. Due to the sliding between rovings, some local locking places can occur during shear deformation, what leads to the local change in the structure of the fabric as well as its mechanical response. The prediction of folding mechanisms in dependency of textile structure and roving type is a desired goal for the design of textile reinforced composites. Still today’s models lack a flexibility to consider multiple factors resulting from different roving properties or different textile properties and correlate this information with a prediction of the folding mechanism. The aim of this project is a prediction of locking shear-angles of textile composite reinforcements.