micropolar elasticity, displacement vector, micro-rotation vector, coupled, vector potential, vortex part, screw equation, screw field, Helmholtz equation, metaharmonic equation, waveguide

The coupled vector differential equations of the linear theory of micropolar elasticity formulated in terms of displacements and micro-rotations are studied. A harmonic dependence of the physical fields on time is assumed. By employing the displacements and micro-rotations representation formula in the terms of four screw vectors a new representation based on two metaharmonic vectors are obtained. Thus the problem of determination of the vortex parts of the displacement and micro-rotation fields is reduced to solution of two uncoupled vector metaharmonic equations. The latter can be oftenly solved by the separation of variables technique. For this reason obtained results can be applied to various problems of the micropolar elasticity related to harmonic wave propagation in waveguides. In particular this is true for waves of a given azimuthal number in a long cylindrical waveguide.

Radayev Yuri Nickolaevich e-mail: radayev@ipmnet.ru, y.radayev@gmail.com, Dr. Sci. Phys. & Math., Professor, Leading Researcher, Institute for Problems in Mechanics of RAS, Moscow, Russia.