No abstract

To avoid resonance, suppress the hull vibration and reduce the noise, vibration characteristics must be predicted during the process of design. The added water mass of the fishery administration ship is calculated for predicting accurately the vibration characteristics. The natural frequency of vertical and horizontal vibration are calculated by FEM method and empirical formula method. The natural vibration characteristics of the target ship under no-load and full-load condition are calculated respectively. The natural frequency of 1st vertical and horizontal vibration which calculated by FEM and calculated by the empirical formula are similar. The natural frequency of the no-load condition is lower than the full load condition.

Abstract. To avoid resonance and make the 300t fishery administration vessel meet the requirements of low vibration and noise, vibration characteristics must be predicted during the process of design. In order to more accurately predict the vibration characteristics, it is necessary to calculate the added water mass. Three-dimensional modeling of the 300t fishery administration vessel is constructed accurately to calculate added water mass. Lewis formula is employed to obtain the added water mass. The added water mass of first three order vertical and horizontal vibration are calculated in this paper. Under the condition of no load, the added mass of vertical vibration is greater than horizontal vibration. Under the condition of full load, the added mass of horizontal vibration is greater.