半潜船振动特性

Vibration characteristics analysis of semi-submerged ship

利用Patran软件建立某半潜船有限元模型,应用Nastran软件的Lanczos方法计算此半潜船在不同载况下船舶总体垂向振动各阶模态。将计算得到的各载况下固有频率与该船主机和螺旋桨激励频率进行比较得出此半潜船振动性能良好。附连水质量对于半潜船各载况下的固有频率有十分重要的影响,因此将以源汇分布法为代表的数值计算方法与刘易斯法为代表的经验公式方法进行验证和对比,得出半潜船下潜状态的附连水质量计算应该应用数值计算方法的结论。本文对于半潜船振动设计预报及附连水质量计算具有一定的参考意义。

Use Patran software build FEM modal of the semi-submerged ship,apply Lanczos method of Nastran software to calculate the ship＇s modes of global vertical vibration in several loading cases.Compare the ship＇s natural frequency in several loading cases to its main engine and propeller＇s excitation frequency,and draw the conclusion that vibration performance of this semi-submerged ship is acceptable.The calculation of added mass water has very important influence of semi-submerged＇s natural frequency in several loading cases,so compare the numerical calculation method such as the source distribution method with the empirical formula method such as F W Lewis method,and get the conclusion that the calculation of added mass water of semi-submerged ship＇s dive load condition should use the numerical calculation method.This paper has certain reference meaning to vibration prediction and calculation of added mass water of semi-submerged ship.