毕业论文(设计)船舶轴系扭转振动的研究

摘 要

轴系在工作过程中，承受着不断变化的扭矩、推力及弯曲力矩作用，因而船舶轴系在运动过程中可能产生以下三种形式的振动：扭转振动，回旋振动和纵向振动。本文主要针对扭转振动的计算进行软件系统的开发。船舶轴系在发动机、螺旋桨等周期性扭矩激励下所产生的周向交变运动及其相应变形即为船舶轴系的扭转振动。

在世界各国的船舶规范中，都列有共同的条款，凡是船用柴油机（主机或辅机）和气轮机动力装置，均必须通过扭转振动的计算，测试的检验，合格之后方可投入运营。 这是因为船舶轴系的扭转振动常常是造成严重事故的主要原因之一，而且扭转振动还常常会诱发船体、动力装置的强烈振动和噪声，传动轴系的断裂，发动机零件磨损的加剧等等问题。

随着柴油机功率、转速的不断提高，与其配套的动力装置样式也越来越多，出现严重的扭转振动现象也就逐步增加了，同时，对船舶轴系扭转振动的研究也得到了进一步的发展。

本文分析了我国轴系扭转振动研究的情况及与世界先进水平相比较的差距;简单介绍了扭转振动的一些理论和计算方法。并以163000DWT油轮为例编写了扭转振动计算的软件。用计算数据做校核计算，得出结论。

关键词: 船舶轴系；计算程序；扭转振动校核

I

Abstract

In the course of shaft to withstand the changing torque, thrust and bending moment of force, and thus shafting in motion that may arise during the following three forms of vibration: vibration, whirling vibration and vertical vibration. In this paper, the calculation of torsional vibration for software system development. Ship shaft in the engine, propeller and other periodic torque generated by excitation of weeks corresponding to the alternating movement and deformation of the ship is the shaft torsional vibration.

Ship in the world specification, the terms are listed together, all marine diesel engines (main or auxiliary) gas turbine power plant, are required by the calculation of torsional vibration, test test, after passing can be put into operation. This is because the ship shaft torsional vibration is often one of the main causes of serious accidents, but also often induce torsional vibration of hull, power plant strong vibration and noise, drive shafts fracture, wear and tear of engine parts and so increase problem.

With the engine power, increasing speed, power plant and its supporting style more and more severe torsional vibration will gradually increase, while the torsional vibration of the ship's research has also been further developed .

This article analyzes the study of torsional vibration conditions and compared with the world advanced level in the gap; brief introduction to some of the torsional vibration theory and calculation methods. And oil tankers as an example prepared by 163000DWT torsional vibration calculation software. Calculation method used to do calculations, draw conclusions.

Keywords: ship shaft; computer program; Check torsional vibration

II

目 录

第一章 绪 论 ............................................................................................................. 1

1. 1船舶轴系的组成与布置 ....................................... 1 1.2船舶轴系的激振力矩 .......................................... 2 1.3轴系扭转振动的简化模型 ........................................................................................ 2 1.4船舶轴系扭转振动的危害 ...................................... 4 第二章 轴系扭转振动的当量计算 ............................................................................. 5

2.1 轴系扭转振动模型建立 ....................................... 5 2.2 转动惯量与扭转刚度计算 ..................................... 5 2.2.1 转动惯量 ........................................................................................................... 5 2.2.1.1旋转运动的转动惯量 ................................................................................. 6 2.2.2 扭振刚度计算 ................................................................................................ 7 2.2.2.1 轴段弹性参数的表示 ................................................................................ 7 2.3 实际轴段的刚度 ............................................ 7 第三章 自由振动计算 ............................................................................................. 9

3.1 自由振动运动方程式 ....................................... 9 3.2 Holzer法 ................................................. 10 3.2.1 Holzer递推式与频率方程式 .................................................................... 10 3.2.2 计算步骤 ......................................................................................................... 11 3.2.3 计算频率的选取 ......................................................................................... 12 3.2.4 计算精度 ....................................................................................................... 12 3.3 传递矩阵法 ............................................... 13 3.3.1 基本概念 ....................................................................................................... 13 3.3.2 状态矢量 ....................................................................................................... 13 3.3.3 元件的传递矩阵 ......................................................................................... 13 3.3.4 计算步骤 ....................................................................................................... 14 3.3.5 扭振许用应力 ................................................................................................ 17

第四章 轴系扭转振动的强迫振动计算 ............................................................... 19

III

4.1 用能量法求强迫振动的近似解 ................................ 19 4.2 系统中阻尼、阻尼功及能量平衡式 ........................... 23 4.3 放大系数法求解共振振幅 ................................... 25 4.4 非共振计算 ............................................... 27 4.5 临界转速的确定 ........................................... 28 第五章 推进轴系扭转振动的控制方案 ................................................................. 30

5.1 调频避振 .................................................. 30 5.1.1 选择合适的飞轮惯量 ................................................................................ 30 5.1.2 改变系统柔度 .............................................................................................. 31 5.1.3 选定适当的螺旋桨惯量 ............................................................................ 32 5.2 平衡外干扰，减少输入系统能量的降幅减振 ................... 32 5.3 增加系统阻尼的降幅减振 ................................................................................... 33 5.4 配置减振器 ............................................... 33 第六章 程序编制说明及结果分析 ....................................................................... 34

6.1 本程序以163000DWT油轮为例编程， .......................... 34 6.2 系统的建立和编程计算过程 ................................. 34 6.3 结果分析 .................................................. 44 结 论 ......................................................................................................................... 45 致 谢 ......................................................................................................................... 46 参考文献 ..................................................................................................................... 47

IV