水面船舶推进轴系回旋振动研究综述

  目的  大型船舶的推进轴系一般具有轴系长、跨度大、细长比小等特点，其弯曲变形与纵向变形之间易存在弹性耦合效应，从而引起轴系异常振动，影响轴系的安全稳定运行。为了研究轴系弯—纵耦合的非线性振动特性，  方法  利用变分原理推导轴系发生弯—纵耦合时的非线性振动方程，采用有限元法（FEM）、打靶法等数值方法，以及多尺度法等近似解析方法对非线性方程进行求解，并对比分析弯—纵耦合效应对轴系非线性振动特性的影响。  结果  计算结果表明：弯—纵耦合效应将导致轴系响应中出现多频响应、跳跃现象、能量迁移等复杂的振动现象，同时将增加轴系弯曲方向和纵向方向的固有频率。  结论  研究成果可为大型船舶推进轴系的工程设计提供参考。

Development of a semi-active dynamic vibration absorber for longitudinal vibration of propulsion shaft system based on magnetorheological elastomer

  Objectives  The propulsion shafting system of large ships usually has the characteristics of long shafting, large span, and small slenderness ratio. Therefore, there is often elastic coupling effect between the bending deformation and longitudinal deformation, which is easy to cause abnormal vibration of the shafting, and affect the safe and stable operation of the shafting system. In order to study the nonlinear vibration characteristics of the shaft under bending-longitudinal coupling effect,  Methods  the nonlinear vibration equations of the propulsion shafting under bending-longitudinal coupling effect were derived by using the principle of variation, and then solved by numerical methods such as Finite Element Method(FEM)and shooting method and by approximate analysis method such as multi-scale method. Then the influence of bending-longitudinal coupling effect on the nonlinear vibration characteristics of shafting was analyzed and compared.  Results  The results show that the bending-longitudinal coupling effect causes complex vibration phenomena such as multi-frequency response, jumping phenomenon and energy transfer in the shafting response, and increases the natural frequencies in the bending and longitudinal direction of the shafting.  Conclusions  The study in this paper can provide reference for engineering design of large ship propulsion shafting.