Influence of disordered fiber arrangement on SH wave transmission in unidirectional composites

The influence of disordered fiber arrangement on the wave transmission characteristics in unidirectional fiber-reinforced composite media is studied numerically based on the eigenfunction expansion and a collocation technique applied to the multiple scattering of the SH (shear horizontal) wave mode. The transmission spectra and the wave amplitude fields are investigated for a regular fiber arrangement in a square array, as well as for perturbed and random fiber arrangements. As a result, certain characteristic features in the transmission spectrum of the regular arrangement, such as the presence of pass and stop bands, are shown to gradually diminish as the fiber arrangement is increasingly perturbed toward randomness. In the random composite, there occur many spots of localized motion with high amplitude, even when the energy transmission in the forward direction is small. It is also shown that the overall trend of the transmission spectrum in the random composite conforms to the theoretical prediction based on the generalized self-consistent scattering model.