Andreas Schnabel

Experimental Setup to Validate Textile Material Models for Drape Simulation

The simulation of the draping process of dry textiles allows one to predict the occurrence of folds and the local fibre orientations and fibre positions after draping. In this paper the experiments to determine the mechanical material properties of textile structures are discussed. The mechanical material parameters are used as input for the drape simulation on the macro-scale. The numeric material models can be validated by comparing the numeric results with the experimental draping results of a drapeability test with standardized geometries. The further developed drapeability test to validate the material models for textile structures will be presented.

Automating textile preforming technology for mass production of fibre-reinforced polymer (FRP) composites

Abstract: Because of their outstanding mechanical properties and low weight, fibre-reinforced composites are a suitable engineering material for many applications. The production of composite parts in high volumes can be realized by a combination of textile preforming processes and liquid composite moulding technologies. In this chapter, various textile preforming technologies are presented and discussed. This includes both single-step preforming processes (e.g., weaving, braiding, production of non-crimp-fabrics) and multi-step preforming processes (e.g., cutting, handling, binder technologies, sewing). Also, future trends for textile preforming are presented.

Mass production technologies for textile reinforcement structures

Abstract This paper reports recent work on the optimisation of preform manufacture. Producing tailored textile semifinished parts, such as non-crimp fabrics (NCFs) with locally adjusted properties, and processing these in a sequence of automated cutting, handling and joining operations are a promising approach to significantly reduce costs and cycle times within preform production. Additionally, along with the enhancement of machinery, the development of simulation tools for designing efficient process chains and understanding the behaviour of reinforcement textiles along the entire production process is essential. The Institut fuer Textiltechnik (ITA) of RWTH Aachen follows this holistic approach, aiming at preforming processes suitable for mass production. In this paper, enhanced production technologies for tailored NCFs are described. Furthermore, an overview of automated technologies for converting these tailored NCFs to near net shape preforms is given. Methodical process chain development is shown in a case study, proving the possibility to significantly increase the operating efficiency of preform production by means of the introduced approach.

Optimisation of the warp yarn tension on a warp knitting machine

Abstract Investigations (calculations) based on a warp yarn tension analysis on a warp knitting machine with multiaxial weft yarn insertion allow prospective reduced yarn tension differences in technical warp knits. From this a future opportunity is provided to substitute the subjective warp let-off adjustment by a model of tension control. The outcome of this is a higher reproducibility with associated increasing process reliability and rising product quality.