A role for industrial looms in craft research

As a definition of craft practice, the workmanship of risk emphasises the judgement and skill of the crafter, as they engage with materials, tools, and techniques to produce artefacts. Through experimental design research methods, self-forming three-dimensional textiles were created with the aim to develop both the use of digital and automated tools for weaving, and language to describe the process of textural forming in weaving when hand and machine meet. Examples of experimental work illustrate the potential of industrial looms as tools for crafting complex textile systems and expressions. The results include a method for crafting at the intersection of the workmanship of risk and CAD/CAM, providing a framework for this hybrid practice, while a new language of textile forming for craft including industrial and CAD/CAM tools emerges.

Towards numerical prediction of flow-induced fiber displacements during wet compression molding (WCM)

Wet compression molding (WCM) provides large-scale production potential for continuous fiber-reinforced structural components due to simultaneous infiltration and draping during molding. Due to thickness-dominated infiltration of the laminate, comparatively low cavity pressures are sufficient – a considerable economic advantage. Experimental and numerical investigations prove strong mutual dependencies between the physical mechanisms, especially between resin flow (mold filling) and textile forming (draping), similar to other liquid molding techniques (LCM). Although these dependencies provide significant benefits such as improved contact, draping and infiltration capabilities, they may also lead to adverse effects such as flow-induced fiber displacement. To support WCM process and part development, process simulation requires a fully coupled approach including the capability to predict critical process effects. This work aims to demonstrate the suitability of a macroscopic, fully coupled, three-dimensional process simulation approach, to predict the process behavior during WCM, including flow-induced fiber displacements. The developed fluid model is superimposed to a suitable 3D forming model, which accounts for the deformation mechanisms including non-linear transverse compaction behavior. A strong Fluid-Structure-Interaction (FSI) enforced by Terzaghi’s law is applied to assess flow-induced fiber displacements during WCM within a porous UD-NCF stack in a homogenized manner. Accordingly, resulting local deformations are considered within the pressure field. All constitutive equations are formulated with respect to fiber deformation under finite strains. Results of a parametric study underline the relevance of contact conditions within the dry and infiltrated stack. The numerically predicted results are benchmarked and verified using both own and available experimental results from literature.

Modelling and Simulation of the Coupling of Normal Pressure and Shear Force in Plain Woven Fabrics

In textile engineering, simulative methods are used more frequently due to their advantages in material and process design. Finite element models were developed for simulating the mechanical and the draping behaviour of fabrics. For large deformation analysis of textile forming, macro mechanical models are employed that use continuum mechanical approaches for matters of reduced computation time. The material data that is required as model input, such as tension and shear properties, can either be obtained by experimental or virtual tests. In such virtual tests the deformation behaviour of fabrics can be determined by deforming the structure on the meso level.

Synthesis and Electronic Properties SWCNT Sheets

ABSTRACTThe commercial synthesis of carbon nanotube sheets will be described. This process involves the following steps: chemical vapor deposition of long CNTs from mixed hydrocarbon type fuels, creation and stabilization of the catalyst, and a large textile forming device. Movies of the growth process will be presented and described. Further the electronic properties of these textiles will be presented and discussed as: (1) A function of temperature from −4 °K to 500 °C, (2) A function frequency from 0 up to about 30 GHz and (3) In a magnetic field up to 1000 Oe. It is shown that these yarns have semiconductor properties but surprisingly exhibit apparent metallic like conduction high at high frequencies. The thermoelectric behavior of the textiles (and yarns) made of this material will be discussed as will the applications in secondary batteries. A power level of up to three watts per gram for the thermoelectric material has been demonstrated.