Modelling and simulation of the hydrodynamic properties of protection and filter fabrics under consideration of service loads to predict their barrier and permeability properties

许多应用要求技术用纺织品兼具规定的透气性和保持性。与非织造布和薄膜相比，单丝或多丝机织面料具有优势。它们可以传递巨大的力量，因此它们在发挥屏障功能的同时，还可以起到支撑作用。这些要求在一定程度上是相反的，因此选择过滤介质是一个非常复杂的问题，其中必须考虑到应用需求和过滤器的特性之间的平衡。该研究项目的目的是对防护和过滤织物在使用负荷下的透气性和阻隔性进行逼真的模拟，以得出一般规律，并有目的地开发具有特定性能的机织物。追求以下科学目标：-表征织物形态和织物特性，用于检测机器参数、工艺参数和织物结构以及织物性能之间的基本关系，-建立基于人工神经网络的一般模型，以预测织物形态和流体动力学(渗透性、颗粒保留率)作为机器和工艺参数的函数，-在微观上理解织物的多尺度形态变化，-考虑面内使用载荷的中观和宏观水平，以及开发在静态和循环加载期间和之后在单轴和双轴应力状态(拉伸和剪切)下原位检测孔几何形状的方法，-在应力作用下微尺度(纱线中的孔)和细观尺度(纱线之间的孔)的孔几何变化的数值模拟、模拟和验证，-使用CFD方法对无应力和受力织物的微观和细观结构中的多相流体动力学特性(渗透性、颗粒滞留)进行建模和模拟，-制定机器和工艺参数与材料参数、由此产生的织物形态以及由气孔形态(如渗透性、滞留和过滤)产生的使用性能之间的联系的规律。在研究项目结束时，应该可以以显著较少的工作量开发基于模拟的纺织品过滤材料。此外，经过验证的模型和已建立的模拟工具应该有助于更深入地理解具有不同功能要求的织物中复杂的滞留机制的基础知识。

Many applications require technical textiles that combine defined permeability and retention properties. Mono- or multifilament woven fabrics have advantages compared to nonwovens and membranes. They can transfer large forces so that they overtake a supporting function in addition to their barrier function. These requirements are partly in the opposite direction so that the selection of a filter medium is a highly complex problem, in which the application needs and the characteristics of the filter must be considered balanced. The aim of the research project is the realistic simulation of the permeability and barrier properties of protective and filter fabrics under service loads to derive general laws and to purposefully develop woven fabrics with specific properties. The following scientific objectives are pursued:- Characterization of the fabric morphology and fabric characteristics for detecting the fundamental relationships between the machine parameters, the process parameters and the fabric construction as well as the fabric properties,- Establishment of a general model based on an artificial neural network to predict the fabric morphology and hydrodynamics (permeability, particle retention) as a function of the machine and process parameters,- Understanding of the multi-scale morphology changes of the fabrics at the micro, meso and macro level under consideration of in-plane service loads and development of a methodology for the in-situ detection of the pore geometry in uni- and biaxial stress states (tension and shear) during and after static and cyclic loading,- Numerical modeling, simulation and validation of the pore geometry changes at the micro scale (pores in the yarn) and meso scale (pores between the yarns) under stresses,- Modeling and simulation of multiphase hydrodynamic properties (permeability, particle retention) using CFD method in micro- and meso-structure for unstressed and stressed fabrics,- Formulation of laws for the connection between the machine and process parameters on the one hand and the material parameters, the resulting fabric morphology and the service properties resulting from the pore morphology (e. g., permeability, retention and filtration) on the other hand.At the end of the research project, it should be possible to develop textile filter materials based on simulations with significantly less effort. In addition, the validated models and the established simulation tools should contribute to a deeper understanding of the basics of complex retention mechanisms in fabrics with different functional requirements.