Experimental and numerical determination of the wave dispersion characteristics of complex 3D woven composites

In this article, an attempt is made towards the experimental validation of a numerical method allowing vibro-acoustic and ultrasonic wave propagation analysis of complex woven composites. For this validation, three different woven architectures were used to manufacture composite samples using resin transfer molding process. For modelling purposes, these composites can be considered as periodic structures composed of unit cells repeated in two directions. The unit cells of these three different woven patterns are modelled realistically at a mesoscopic scale, using information from micrographic cross-sections and the mechanical properties of the fibres and matrix materials provided by the manufacturers and the literature. The numerical method, combining the mode-based component mode synthesis and the wave finite element methods, allows for computing the dispersion relations of the modelled samples. Experimentally, dispersion relations are extracted from the samples by means of a linear scan of a wave measured by a laser vibrometer and generated by a piezoelectric transducer. The modelling methodology is thus validated experimentally and shows a good accuracy for determining the dispersion relations of complex woven composites. It is feasible computationally and provides a deeper understanding of the dispersion relations than experimental testing.