Flexural-Gravity Waves in an Ice Cover Exited by Periodically Varying Moving Perturbations

The vibrations of a floating ice cover under the action of moving disturbances of variable intensity are studied. The model of vibrations of a floating ice cover is based on the linearized fluid mechanics equations and the linear classical theory of vibrations of plates. The ice cover is considered as a thin elastic isotropic plate. The critical velocities at which the nature of the wave disturbances changes both in front of the disturbance source and behind it are determined. The critical velocities as functions of the source oscillation frequency are studied, six critical velocities being obtained. It is shown that from one to seven wave systems are formed depending on the velocity of the source and the frequency of its oscillations. The corner zones in which these waves are formed are determined. The effect of compression and tension forces on the critical velocities and the corner zones in which the waves propagate has been studied.