Y. Mao, M. Warner, E. M. Terentjev, R. C. Ball
Cavendish Laboratory, Madingley Road,
Cambridge, CB3 OHE, UK.
We present a model calculation of the elasticity of a nematic
elastomer of finite-lengthed network strands under affine deformation.
The result is derived in its full tensorial structure, and its
predictions are examined. In particular, we look at the non-Gaussian
corrections to the effects of soft elasticity and elastic anisotropy.
We find that the soft modes can at most be hardened
at 
when compared to the conventional rubber elastic energy,
where N is the number of monomer units along a typical strand.
The elastic moduli for extensions parallel and perpendicular
to the nematic director are found to differ at .