NCF--CAE: Simulation of Non-Crimp Fabrics based on Computational isogeometric shell elements, Analytical averaging and Experimental analysis

NCF--CAE：基于计算等几何壳单元、分析平均和实验分析的无屈曲织物模拟

• 批准号: 408311698
• 负责人: Professor Dr.-Ing. Thomas Gries
• 金额: --
• 依托单位: Institut für Textiltechnik (ITA)
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2018
• 资助国家: 德国
• 起止时间: 2017-12-31 至 2022-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/408311698?language=en
• 关键词: NCF; CAE; Simulation; Non; Crimp

Non-crimp fabrics (NCFs) are textile reinforcement structures for composites with straight (non-crimped) fibers. Due to their economical fabrication, NCFs have become prominent in the automotive and aeronautic industry. The complex interactions between the fibers and plies lead to significant challenges in the computational modeling of NCFs. To the best of our knowledge, there is no computational framework able to reproduce the complex material behavior of NCFs in a precise and numerically efficient way.The main objective of the project is to advance the computational technology for the simulation of draping processes of NCFs in terms of both accuracy and efficiency. To this end, a computational framework for NCFs based on an isogeometric rotation-free shell formulation and different constitutive models is developed and the accuracy of this framework is investigated. The proposed material models take into account all important deformation mechanisms of NCFs, such as stretching, bending and anisotropic in-plane shear response, intra-ply and inter-ply sliding, as well as the change in fiber volume fraction. So far, all these features have not been captured in a single framework.The proposed computational shell formulation will allow the efficient and robust simulation of textile behavior including the presence of structural instabilities such as wrinkling and in-plane shear instability. For the development of the computational framework, the deformation mechanisms of NCFs are studied by detailed experimental analysis. The acquired data provide a basis for development of material models and their validation. By this experimental study, the influences of the NCFs properties on the deformation behavior are identified and complemented.The result of the project is a validated new computational framework that has a better efficiency, accuracy, and robustness in comparison to classical finite element method approaches for the draping simulation of NCFs. Additionally, all deformation mechanisms of NCFs are comprehensively understood. In order to disseminate the research results, the new finite element routines will be posted online at the end of the project for free downloading.

无卷曲织物（nfc）是用直（无卷曲）纤维制成的复合材料的纺织增强结构。由于其经济的制造，nfc已成为突出的汽车和航空工业。纤维和层之间复杂的相互作用给nfc的计算建模带来了巨大的挑战。据我们所知，目前还没有一种计算框架能够以一种精确而高效的方式再现nfc的复杂材料行为。该项目的主要目标是在精度和效率方面推进nfc悬垂过程模拟的计算技术。为此，建立了基于等几何无旋转壳公式和不同本构模型的nfc计算框架，并对该框架的精度进行了研究。所提出的材料模型考虑了nfc的所有重要变形机制，如拉伸、弯曲和各向异性面内剪切响应、层内和层间滑动以及纤维体积分数的变化。到目前为止，还没有在一个框架中捕获所有这些特性。所提出的计算壳公式将允许纺织行为的有效和稳健的模拟，包括结构不稳定的存在，如起皱和面内剪切不稳定。为了发展计算框架，通过详细的实验分析研究了nfc的变形机理。所获得的数据为材料模型的开发及其验证提供了基础。通过试验研究，识别和补充了nfc性能对变形行为的影响。该项目的结果是一个经过验证的新的计算框架，与传统的有限元方法相比，该框架具有更好的效率、精度和鲁棒性，用于nfc的悬垂模拟。此外，还全面了解了nfc的所有变形机制。为了传播研究成果，新的有限元例程将在项目结束时发布在网上，供免费下载。