Computational simulation of harmonic wave propagation in fibrous micro- and nanocomposites

In this paper, deformation due to plane harmonic waves propagating along the fibres and polarised perpendicular direction is considered. To describe the behaviour of the material, a second-order continuum theory, namely the theory of two-component elastic mixtures, is used. Analytical solution to the problem is derived and then used to study wave propagation phenomena in fibre reinforced composite materials with epoxy matrix. Four types of fibres are considered: Thornel-300 carbon fibres; carbon whiskers; zigzag carbon nanotubes; chiral carbon nanotubes. Theoretical analysis and numerical results indicate that in unidirectional fibre-reinforced micro- and nanocomposites, the second mode of the transverse wave, propagating along the fibres and polarised perpendicularly to the fibre direction, can be critical to the strength of the material at high frequencies. This mode generates anti-phase vibrations in the composite constituents and forces that could cause interfacial debonding. This phenomenon can be classified as a possible new mechanism of debonding.