船体结构刚度对桅杆振动特性的影响及控制

Influence of the ship-hull structure stiffness on the mast vibration parameter and its control

采用Euler Bellouli梁理论推导出桅下船体结构旋转刚度和桅杆首阶固有频率参数之间的关系.用桅下船体结构的旋转刚度kα和桅杆参数EIl的比值判断桅下船体结构的旋转刚度对首阶固有频率的影响,对一个安装在不同旋转刚度基础上的桅杆实例进行了有限元计算,找出了桅下船体结构旋转刚度的合理设计范围.有限元软件仿真计算结果表明,合理地选择kα值可使桅杆首阶振动频率得到主动控制.

In this paper, the relation between the ship-hullstructure rotation stiffness k_α under mast and the mast′s first natural frequency parameteris educed by use of Euler-Bellouli beam theory. The affection of the ratio of k_α and the mast parameter EIl for first natural frequencyis discussed, too. After the finite elementcalculation for a practicalexample of mast installed on the different rotation stiffnessbases, the reasonabledesign boundsfor ship-hullstructure rotation stiffness k_α under mast are found. On the basis of this work, it is concluded that the first natural frequency of mast can be controlled activelyby the rationalselection of k_α.