ИСТИНА

It is known that the eigenvalues of the tensor and the tensor-block matrix are invariant quantities. That is why the aim of this work was to find the expressions for the velocities of wave propagation of some media through the eigenvalues of the material tensors. In particular, it is considered materials with the anisotropy symbol {1.5} and {5.1}, as well as isotropic materials, and expressions for the velocities of wave propagation for them are given. In addition, the expressions for the velocities of wave propagation for materials of cubic syngony with the anisotropy symbol {1,2,3} (the matrix of the elastic modulus tensor components has three independent components), hexagonal system (transversal isotropy) with anisotropy symbol {1,1,2,2} (the matrix of the elastic modulus tensor components has five independent components), trigonal system with anisotropy symbol {1,1,2,2} (the matrix of the elastic modulus tensor components has six independent components), tetragonal system with anisotropy symbol {1,1,1,2,1} (the matrix of the elastic modulus tensor components has six independent components) are obtained. There are also obtained the expressions for the velocities of wave propagation for a micropolar medium with the anisotropy symbol {1.5.3} and {5.1.3}, as well as for an isotropic micropolar material.