Research On Lateral Vibration For Slightness Shafting With Elastic Base On The Hovercraft

The propulsive shafting is an important part of the dynamic system on the marine. And the survival ability of the marine dynamic system depends on the vibration of the shafting directly. The theoretical model of the shafting for the lateral vibration is established in this article according to the characteristics and structures of the shafting on the hovercraft. The free and forced lateral vibration of this shafting is calculated using the finite element method. And the results are proved to be correct by the means of measuring on the test bench.The natural frequencies and the mode shapes of the lateral vibration are determined by the research on the free vibration for the propulsive shafting. The FEM model of the existing hull is established, and the rigidity of the float hull is considered. The forced response analysis is performed by the research on the forced vibration in which the effect of the float hull is considered under the external force. The theoretical and experimental studies on the infective factors are also performed. The vibration experiments are carried out on the test bench, and the obtain results show the accuracy of the theoretical model and the objectivity of the analysis method.Finally the vibration analysis on the entire hovercraft is performed in which the effect of the shafting to the hull is analyzed. And the characteristics of the hovercraft are studied when the hovercraft experiences the waves. The vertical displacements of the typical nodes on the hull and shafting under the limit distortion are listed in the appendix, which provide the theoretical basis for the security of the shafting and hovercraft.