Analysis of torsional vibrations of a ship propeller shaft

Today, the basic principle in the production of machines and power transmission parts (shafts and reducers) that enables the vehicles used in land, air and marine transportation to move is to increase the power and economic life of the machines by increasing the working cycles by producing the machines with light and high strength materials. Because of the increase in the number of revolutions of the machine and the subsequent increase in power, the vibrations that occur in the machine and transfer parts arise as an important problem to be solved. The neglect of the unbalanced inertia centrifugal forces in the design calculations of the vehicle motion and transmission systems causes large vibrations in the vehicle motion and propulsion systems. Due to these vibrations to occur in the resonance zone, the transfer parts providing the movement of the vehicle will be broken before the calculated working life. By taking into account the resonance frequencies of the free and forced vibrations of the transfer parts that allow the vehicle to move, it is necessary to take operational measures which will prevent the machine from operating in the resonance zone. With this solution, It is ensured that the revolutions in the resonance zone are entered into a short period of time and that the output is accelerated and slowed down. In order for the used machinery and transmission systems to operate efficiently and continuously, it is necessary to prevent the radial (torsional) and torsional (torsional) vibrations that occur in the transmission parts during operation from generating large amplitudes in the resonance region. With the natural frequency equations found, the operating cycles or intervals of the mechanical transmission systems of the ships to be designed shall be determined so as not to work at the resonance frequencies and the necessary warnings about the operating cycles of the machines shall be made to the users.