计入船体变形影响的轴系动态校中研究

Study of dynamic shafting alignment considering ship hull deformations

船体变形是影响船舶推进轴系校中质量的一个非常重要的动态因素.在研究船舶装载、波浪荷载及环境温度作用下船体变形计算方法的基础上,提出了一种轴承变位的计算方法,用以进行轴系动态校中研究.以76 000t成品油轮为例,计算了极限装载状态下的重力分布和常遇较大海况时的波浪荷载,并分析了环境温度荷载分布.通过对整船有限元模型合理施加荷载及模拟水弹性约束,得到船体二层底的变形.在此基础上,分别拟合船体二层底变形曲线及其随船体产生的纵倾,求解轴承变位,并以空船静水状态作为船体变形的基本状态,实现了计入船体变形影响的轴系动态校中.

Ship hull deformation is one of the most significant dynamic influences on propulsion shafting alignment.The calculation fundamentals of ship hull deformations in different conditions of ship loading,wave loads and environment temperature fields are studied,as well as the convention method of hull deformations to bearing offsets.Then,a new method of dynamic shafting alignment considering ship hull deformations is proposed.Especially,76 000DWT product oil tanker is taken for example.The ship loadings,wave loads and environment temperature differences in some extreme conditions,as well as elastic restraints,are simulated and applied to the finite element model of the whole ship,so that the deformations of the double bottom can be solved. The deformation curves and trim lines of the double bottom are fitted to calculate bearing offsets.Taking the condition of light ship in calm water as a reference,dynamic shafting alignment considering ship hull deformations is realized and optimized.