Buckling instabilities in nematic elastomers

Tuesday, May 24, 2005 - 11:00am - 11:35am
EE/CS 3-180
Robert Meyer (Brandeis University)
Buckling instabilities are well known in the mechanics of elastic beams under compressive stress. Intuitively, for ordinary elastic materials, it is clear that tall thin beams buckle easily, while short thick ones do not buckle at all. For nematic elastomer materials, these intuitive ideas break down, because of the extreme anisotropy of these materials. For nematic elastomers, certain shear deformation modes exhibit soft elasticity, meaning that these modes are characterized by a vanishing shear modulus. This has the consequence that nematic elastomers are often subject to buckling instabilities, even for sample geometries that would only allow simple linear elastic response, were the sample composed of an ordinary elastic medium. Examples of these instabilities in several sample geometries will be discussed, along with some experimental results.