Mechanical modelling of monofilament technical textiles

The mechanical behaviour of textiles is often of great importance in several industrial applications. This is the case for textile reinforcement used in composites or for technical textiles. In composites manufacturing and in particular in the processes of forming and consolidation of composites, properties as in-plane shear and tensile behaviour are, together with the transversal compaction of the yarns, the most important features. In the case of monofilament technical textiles used in the screen printing industry, mechanical properties such as the response of the fabric to contemporary actions of in-plane tensile and local bending are considered of primary interest. In all the cases the experimental characterisation is not sufficient and must be integrated with analytical or numerical models of the fabrics. This paper presents a numerical model to evaluate the mechanical properties of dry monofilament technical textiles. At the same time an experimental campaign was undertaken both to evaluate the main mechanical features and to calibrate the numerical model. Several monofilament textile geometries were examined and the tests were carried out on single fibres, to determine their tensile and friction properties, and on specimens cut from the textile to determine both the axial and biaxial behaviour. The macroscopic mechanical features of the monofilament textiles are obtained at the mesoscale level with a model of the representative volume (RV) assuming the periodicity in the textile geometry. The resulting macroscopic mechanical properties of the textile are used in the simulation of a structural cylindrical component for screen printing applications. The proposed numerical model appears to be a tool for the design of various applications of technical textiles where the mechanical aspects are essential. (C) 2007 Elsevier B.V. All rights reserved.