Spatial modelling of 3D-woven textiles

When analysing for instance permeability and mechanical behaviour of advanced textiles, a representative description of the textiles' architecture is desired. Realistic geometric representations of textiles are however often either difficult to obtain due to limitations in modelling tools, or judged unfeasible to generate due to unreasonable modelling efforts. In this paper a scheme is presented that enables modelling of the internal strand geometry including details of the strand path and smoothly varying cross-section size and shape, on a meso-scale. The main modelling artifice is to initially model the strand perimeters as inflatable tubes in an explicit finite element simulation. The tubes are initially made slender to avoid strand inter-penetration, and then expanded under general contact conditions until the desired volume fraction of strand is reached. For validation a model is compared with pictures from a computer tomography scan of a 3-dimensionally woven carbon fibre preform. The correlation between the simulated geometry and the real sample is striking. The results also indicate that the approach is relatively robust in terms of sensitiveness to variations of input data and starting conditions.