“dynamics of Viscoelastic Anisotropic Media”

New principles are introduced for the formulation of dynamic problems in viscoelasticity for the most general case of anisotropy. One is a variational principle derived from irreversible thermodynamics. The other a correspondence principle between viscoelasticity and elasticity. Applications to the mmics of viscoelastic plates and rods are developed as examples. The variational principles are applied in conjunction with a very general method of approximation by expanding the deformation in a power series across the thickness. The method is applicable to viscoelastic shells. The concept of partial mode as a generalization of that of vibration mode for the elastic case is also introduced.