Abstract
A harmonic wave of a fixed frequency propagates across the periodic system of elastic layers. The elementary cell consists of three layers. The transfer matrix M may be expressed by two real parameters ϕ, ψ and a set P of 64 further scalar parameters M = M(ϕ, ψ, P). The parameters are uniquely defined for the particular M and may be calculated from a system of trigonometrical equations. It has been proved numerically that, for materials and dimensions given in advance, this function for each integer n satisfies the identity [M (ϕ, ψ, P)]n = M (nϕ, nψ, P). The derived identity drastically simplifies the calculation of displacements and stresses in the periodically layered medium.
References
Z. WESOŁOWSKI, Algebra of the transfer matrix for layered elastic material, Arch. Mech., 45, 2, 191-210, 1993.
Z. WESOŁOWSKI, Products of the transition matrices governing the dynamics of set of elastic layers, Bull. Pol. Acad. Sci., Math., 40, 1, 53-57, 1992.