The Research On The Dynamic Response Of The Propulsion Shafting In Naval Ship

The propulsion shafting is one of the most essential parts of ship's powder system. The reliability and stabilization of the running propulsion shafting effects the vessel's operation directly. The propulsion shafting is subjected to the various dynamic factors when it is running, including hydro-oscillation force, ship hull'distortion, lubricative oil force and so on. For the naval ship, shock forces such as contactile explosion, underwater uncontactile explosion and the bounce-back force caused by weapon's emission may probably befallen to the propulsion shafting. Of late years, with the development of huge shafting, the vibration problem becomes more severe, and this usually causes grave vibration of the ship's rear part. Consequently, dynamic characteristic analysis of the propulsion shafting is of theoretical and practical significance.First this paper analyzes the torsional vibration and whirling vibration of the propulsion shafting under the hydro-oscillation force. For the study of torsional vibration, lumped mass-continuous elastomer model of the propulsion shafting is established, and the transfer matrix method is used for the calculation of the shafting's natural frequency and the vibration response under the hydro-oscillation force. For the study of whirling vibration, finite element model of the propulsion shafting is established. Then, by eigenvalue analysis, the whirling vibration natural frequency is achieved, and the vibration response under the hydro-oscillation force is calculated by the Newmark algorithm.Furthermore, this paper analyzes the dynamic response of the propulsion shafting under the shock load caused by underwater uncontactile explosion. First, the method for handling shock load is studied, and the explosion shock wave is simulated. Then, the Newmark algorithm is used to handle the shock wave, and a program is formed. Finally, using the same finite element modal as used in studying the whirling vibration before, the dynamic characteristics under explosion shock wave is studied. The displacement of the key nodes on the shafting is calculated and the stress at every bearing is then worked out.