Calculation the Influence of Ocean Waves on Shafting Based on 3-D FEM

Wave is one of the main reasons to cause the hull deflection which result in shaft alignment problems. The 3-D FEM model of a bulk carrier is carried out in this paper. The wave pressure is calculated and loaded automatically based on Patran command language. The deformations of ship construction in various sea waves are calculated and the effect to bearing load is analyzed. The result shows: The deflection of hull under shaft line is small in the sea state 4 and under the sea state 4. The deflection of hull under shaft line is increased by sea state. And it is more than 4 mm in the sea state 8, the shaft bearings load will be affected enormously. The influence of course angle to hull deflection is different in different sea condition. This method can predict hull deflection and bearing reactions in different sea condition and different course angle.