Numerical and experimental analysis of permeation and cracking behavior of fiber reinforced plastic composites with thermoplastic matrix system

实现温室气体中和对于限制人为造成的气候变化至关重要。在德国，这一目标要在2045年实现。在即将到来的技术变革中，氢作为一种多功能的环保能源载体（如果使用可再生能源生产），在几乎所有的场景中都发挥着关键作用，以确保能源转型和气候保护的长期成功。在现有的氢存储系统中，由纤维增强塑料复合材料（FRP）制成的加压存储系统由于其相对高的存储密度和低质量，代表了用于移动的应用的有前景的技术。特别是，科学家和工程师正在关注所谓的多单元存储系统，该系统提供圆柱形槽单元的回路，从而可以有效和灵活地利用可用的安装空间。然而，缺点是减小的护套表面与储存体积的比率，这意味着需要更高的衬里壁厚度来满足渗透和泄漏要求。这个问题的一个解决方案是无衬里设计（V型压力罐），其中FRP同时用作支撑结构和渗透屏障。然而，V型设计的实施需要深入了解FRP的渗透行为。由于压力容器壁的高载荷，必须研究损伤对渗透的影响，以便通过适当的材料和结构设计来克服这些挑战。在此背景下，本项目的主要目标是定性和定量分析以及基于模型的描述热塑性基体连续增强纺织复合材料（PA 6）的渗透行为。为此，在CT成像分析领域的实验方法以及通过相场法的数值裂纹建模将被推进并用于裂纹图案的分析。基于人工智能的裂纹预测、量化和分类模型的开发、验证和贡献，为未来的纺织品结构渗透评估做出贡献。此外，在原位渗透试验中研究了裂缝张开度的影响，并建立了渗透数值模型。将提供一个深刻的理解与纺织增强结构的复合材料的裂纹和渗透现象之间的相关性，以建立一个成功的设计和布局的无衬里结构高效的压力罐和管道的基础。

Achieving greenhouse gas neutrality is essential to limit human-caused climate change. In Germany, this goal is to be achieved by 2045. In the upcoming technological change, hydrogen plays a key role in almost all scenarios as a versatile and - if produced with renewable energies - environmentally friendly energy carrier to ensure the long-term success of the energy transition and climate protection.Among the available storage systems for hydrogen, pressurized storage systems made of fiber-reinforced plastic composites (FRP) represent a promising technology for mobile applications due to their comparatively high storage density and low mass. In particular, scientists and engineers are focusing on so-called multi-cell storage systems, which provide a circuit of cylindrical tank cells and can thus make efficient and flexible use of the available installation space. A disadvantage, however, is the diminished sheath surface -to-storage volume ratio, which means that higher liner wall thicknesses are required to meet permeation and leakage requirements. One solution to this problem is linerless designs (Type-V pressure tanks), in which the FRP simultaneously functions as a support structure and permeation barrier. However, the implementation of the Type-V design requires an in-depth understanding of the permeation behavior of FRP. Due to the highly loaded pressure tank walls, the influence of damage on permeation must be investigated to be able to overcome the challenges through adapted materials as well as structural designs.With this background, the primary objective of the project is the qualitative and quantitative analysis as well as the model-based description of the permeation behavior of continuous reinforced textile composites with thermoplastic matrix (PA 6). For this purpose, experimental methods in the field of CT imaging analysis as well as numerical crack modeling by means of the phase field method will be advanced and used for the analysis of crack patterns. AI-based models for crack prediction, quantification and classification are developed, validated and contribute for future permeation assessment of textile architectures. Furthermore, the influence of crack opening is investigated in in-situ permeation tests and a numerical permeation model is derived. A profound understanding of the correlation between crack and permeation phenomena for composites with textile reinforcement architectures will be provided in order to establish the basis for a successful design and layout of linerless construction-efficient pressure tanks and pipelines.