THE EFFECT OF VISCOELASTIC BRAIN ON THE DYNAMIC CHARACTERISTICS OF THE HUMAN SKULL-BRAIN SYSTEM

In this paper, we present a solution to the problem of free vibrations of the human head system taking into account the dissipative behaviou r of the brain. The mathematical model is based on the three-dimension al theory of viscoelasticity and the representation of the displacemen t field in terms of the Navier eigenvectors. The frequency equation is solved numerically and the results for eigenfrequencies and damping c oefficients are presented for various geometrical and physical paramet ers of the system. The results obtained are in excellent agreement wit h the measured eigenfrequencies, and the predicted damping coefficient s are within the order of magnitude of the measured ones. From the pro posed analysis we have obtained the information that the role of the v iscoelastic neck as well as the viscoelastic properties of the skull-b rain system have to be simultaneously taken into account in the study of the frequency spectrum of the human head. The analysis of the reali stic model is under preparation.