Surface and Guided Waves in Composites with Nematic Coatings

The theoretical prediction of the acoustical polarization effects in the heterogeneous composites, made of thick elastic solids with thin nematic films, is presented. The numericalanalytical solution to the problem of the different wave propagation exhibits some new physical effects in the low frequency domain: the appearance of the critical frequency and the existence of the narrow transition zone where the wave rapidly changes its speed. The associated wave attenuation is highly perturbed in this zone. We also show the possible appearance of the critical frequencies where the attenuation changes the sign. The numerical results of parametrical analysis are presented and discussed.




References:
[1] H. R. G. Brand, and H. Finkelmann, "Physical properties of liquid
crystalline elastomers". Handbook of liquid crystals (ed. Demus D. et
al.) Wiley: 1998.
[2] P.-G. de Gennes, J. Prost, "Physics of liquid crystals" Oxford:
Clarendon, 1993.
[3] E. M. Terentjev, "Liquid-crystalline elastomers", J. Phys. Condens.
Matter, Vol. 11, 1999, pp. 239-257.
[4] E. M. Terentjev, and M. Warner, "Linear hydrodynamics and
viscoelasticity of nematic elastomers", Eur. Phys. J. E, Vol. 4, 2001, pp.
343-353.
[5] E. M. Terentjev, I. V. Kamotskii, D. D. Zakharov, and L. Fradkin,
"Propagation of acoustic waves in nematic elastomers", Physics Review
E, vol. 66(5), 2002, pp. 770-773.
[6] L. Fradkin , I. V. Kamotskii, E. M. Terentjev, and D. D. Zakharov,
"Low frequency acoustic waves in nematic elastomers", Proceedings of
Royal Society London A, vol. 459, 2003, pp. 2627-2642.
[7] J. Schmidtke, W. Stille, and G. Strobl, "Static and dynamic light
scattering of a nematic side-group polysiloxane", Macromolecules, Vol.
33, 2000, pp. 2922-2928.
[8] M. Schoonstein, W. Stille, and G. Strobl, "Effect of the network on the
director fluctuations in a nematic side-group elastomer analysed by static
and dynamic light scattering", Eur. Phys. J. E, Vol. 5, 2001, pp. 511-
517.
[9] K. F. Graff, "Wave Motion in Elastic Solids" N.Y.: Dover Publ., 1975.
[10] G. A. Korn and T. M. Korn, "Mathematical handbook", McGraw-Hill,
1968.
[11] A. L. Shuvalov and A. G. Every, "Some properties of surface acoustic
waves in anisotropic-coated solids, studied by the impedance method",
Wave Motion, Vol. 36, 2002, pp. 257-273.