Surface waves propagating along the edge of a plate (edge waves) are investigated. The case of symmetrical vibrations of a plate with free or fixed faces is considered. The sides of the plate are subjected to mixed boundary conditions. The motion of the plate is assumed to be described by 3D theory of elasticity, which allows to study higher order edge waves. The vibrations are exited by normal edge load. The numerical results for first four higher order edge waves are presented. The asymptotical estimates are obtained for phase velocities as the wave number tends to infinity. In the short-wave limit the phase velocities of higher order edge waves tend to the velocity of Rayleigh wave. In the case of free faces all higher order edge waves are damped by radiation of energy with propagating waves, but for short waves the damping becomes small. In the case of fixed faces there is no fundamental edge wave, but an infinite spectrum of higher order edge waves. For each fixed wave length there exist several non-damped waves, but the other waves of the spectrum are damped.
|
