Measurement and modeling of the unsaturated out-of-plane permeability and high-pressure impregnation of reinforcing structures

在液态复合材料成型（LCM）工艺中，快速织物浸渍技术通常依赖于面外注射策略，以提高生产率并进一步增强复合材料解决方案的竞争力。为了进一步优化经济效益，浸渍过程可以在高达200巴的高压条件下进行。由于树脂流动和纤维床变形之间的强耦合，离面浸渍过程难以建模。本项目的目的是研究潜在的浸渍机制和知识的应用，以开发可靠的方法和工具，用于表征高压条件下增强结构的非饱和面外渗透性。为了实现这一目标，分析和数值研究相结合的新的实验方法，包括流量和铺层位移监测技术。这些见解将被转换为一种强大的和时间效率高的平面外渗透率测量方法，该方法基于快速算法，能够提取可靠的渗透率值，同时考虑到最少的测量次数。为了解决这一具有挑战性的任务，ETH Zürich CMASLab的Paolo Ermanni博士教授和申请人决定联合起来，分享他们互补的知识和专业知识。IVW和CMASLAb之间的良好合作已经在之前的DACH项目中得到了展示。IVW将继续专注于方法和实验研究的开发，包括测量单元的开发和实现，并在不同条件下（包括高压条件）进行流动实验。CMASLab将开发数值方法和相关工具，从实验数据中推导出非饱和渗透率。通过合作，单个研究中心的贡献将得到宝贵的扩展。

In Liquid Composite Molding (LCM) processes, fast textile impregnation techniques often rely on out-of-plane injection strategies, in order to increase production rates and further enhance the competitiveness of composites solutions. For further optimization regarding economic efficiency, the impregnation process can be under high pressure conditions up to 200 bar. The out-of-plane impregnation process is difficult to model because of the strong coupling between resin flow and fiber bed deformation. The objective of this project is to investigate the underlying impregnation mechanisms and the application of knowledge for development of reliable methods and tools for the characterization of the unsaturated out-of-plane permeability of reinforcing structures under high pressure conditions. To achieve this target analytical and numerical investigations are combined with new experimental methods, including flow and ply displacement monitoring techniques. The insights will be transferred into a robust and time-efficient out-of-plane permeability measurement method based on fast algorithms capable to extract reliable permeability values considering a minimal number of measurements. In order to address this challenging task, Prof. Dr. Paolo Ermanni, ETH Zürich CMASLab and the applicant have decided to join forces, sharing their complementary knowledge and expertise. The excellent cooperation between IVW and CMASLAb has already been shown on the preceded DACH project. IVW will continue in concentrating on the development of methods and experimental investigations, including the development and the realization of the measurement cell and carry out flow experiments under different conditions (including high pressure conditions). CMASLab will develop the numerical methods and related tools to derive the unsaturated permeability from the experimental data. The contributions of the single research sites will be valuably extended through the collaboration.