FREQUENCY-SPECTRUM OF THE BISPHERICAL HOLLOW SYSTEM - THE CASE OF THENONUNIFORM THICKNESS HUMAN SKULL

In the present work we discuss the role of the thickness nonuniformiti es of the human dry skull on its frequency spectrum. The mathematical modelling is based on the three-dimensional theory of elasticity, the approximation of the skull by an isotropic material occupying the regi on bounded by two non-concentric spheres and the introduction of the b ispherical coordinates system. The mathematical analysis is based on t he construction of the Navier eigenfunctions of the problem and the re presentation of the solution in terms of them. The frequency equation is solved numerically and the role of various parameters entering the problem is extensively discussed.