| Abstract: | We consider the problem of determining necessary and sufficient conditions for the existence of symmetry planes of an anisotropic elastic material. These conditions are given in several equivalent forms, and are used to determine special coordinate systems where the number of non-zero components in the elasticity tensor is minimized. By the method presented here it is also shown that an elastic solid has at least six coordinate systems with respect to which there are only 18 non-zero elastic constants and cannot possess more then ten traditional and distinct symmetrics by planes of symmetry. |
