4. Excitation of ship vibrations by propellers

The increase in size and tonnage of cargo ships and oil tankers, or in the speed of container ships and speedboats, has led to an increase in the power installed on board, and a corresponding rise in the level of vibration excitations generated by engines and propellers. In addition, the development of finite element fatigue calculation programs has led to structural lightening, and consequently to lower natural vibration frequencies, the lowest of which can be in the range of propeller excitations.

These vibratory phenomena are dangerous for the hull structure, and disturb personnel and the operation of certain equipment. It is therefore important, among other things, to be able to pinpoint the causes of vibration excitation by the propeller, so as to be better able to remedy the situation.

We can distinguish two sources of vibration excitation...