SH waves of an arbitrary frequency in random fibrous composites via the K-K relations

The Kramers-Kronig relations method is shown to provide the dynamic response of a random fibrous composite for the full frequency interval, 0 < ω < ∞. The method yields a conceptually simple way of deriving the dynamic response of random composites if the approximation of an effective homogeneous medium is adopted. It is shown that some of the widely accepted theories may violate the causality and/or linearity of the effective medium. Extensive numerical data are given as well as comparison with other theories and experiments.