﻿ 基于应力测量和响应技术的船舶结构可靠性监测
 舰船科学技术  2022, Vol. 44 Issue (18): 61-64    DOI: 10.3404/j.issn.1672-7649.2022.18.013 PDF

1. 中国船级社 青岛分社建造处，山东 青岛 266000;
2. 启东中远海运海洋工程有限公司，江苏 启东 226251

Reliability monitoring of ship structure based on stress measurement and response technology
LI Qing-han1, YUAN Yu-bo2
1. China Classification Society Qingdao Branch Newbuildings Department, Qingdao 226000, China;
2. COSCO Shipping (Qidong) Offshore Co., Ltd., Qidong 226251, China
Abstract: The fatigue failure of ship structure will occur under the action of various loads such as waves for a long time. In order to ensure the safety of ship operation and monitor and identify the stress failure of ship structure in advance, this paper designs a ship structure reliability monitoring system based on stress measurement and response technology, and introduces the principle of ship structure stress data collection, the working principle of fiber grating sensor The main structure of the structural reliability monitoring system, and the stress data measurement simulation of the ship deck structure under the wave load is carried out by combining the software program. This research has important significance for improving the navigation safety of ships and improving the ship monitoring level.
Key words: stress measurement     response     statistical principle     fiber grating     reliability
0 引　言

1 船舶结构应力测量和响应技术的研究现状 1.1 船舶结构应力测量统计原理

 图 1 船舶应力幅值的Rayleigh分布示意图 Fig. 1 Rayleigh distribution diagram of ship stress amplitude

 $\left\{ {\begin{array}{*{20}{l}} {\bar X = \displaystyle\frac{1}{n}\sum\limits_{i = 1}^n {{x_i}}，} \\ {{S^2} = \displaystyle\frac{1}{{n - 1}}\sum\limits_{i = 1}^n {{{\left( {{x_i} - \bar X} \right)}^2}} 。} \end{array}} \right.$

j个样本数据的原点矩为：

 ${A_j} = \frac{1}{n}\sum\limits_{i = 1}^n {x_i^j} \text{，}$

 ${B_i} = \frac{1}{n}\sum\limits_{i = 1}^n {{{\left( {{x_i} - \bar X} \right)}^i}} 。$

 $\mathop {\lim }\limits_{n \to \infty } {B_2} = \frac{1}{{n - 1}}\sum\limits_{i = 1}^n {{{\left( {{x_i} - \bar X} \right)}^2}} = {S^2} \text{。}$

 $\left\{ {\begin{array}{*{20}{l}} {\bar X = {A_2}，} \\ {{S^2} = {B_2}。} \end{array}} \right.$

 $\left\{ {\begin{array}{*{20}{l}} {E\left( x \right) = {A_2}，} \\ E\left( {{x^2}} \right) = {B_2}，\\ D\left( x \right) = E\left( {{x^2}} \right) - {\left( {E\left( x \right)} \right)^2}。\end{array}} \right.$

 $E\left( X \right) = \frac{{\displaystyle\sum\limits_{i = 1}^m {{n_i}{{\bar X}_i}} }}{{\displaystyle\sum\limits_{i = 1}^m {{n_i}} }} 。$
1.2 船舶结构应力测量中光纤光栅传感器技术的应用

 图 2 应力测量采用的光纤光栅传感器原理 Fig. 2 Principle of fiber grating sensor used in stress measurement

 ${\lambda _E} = 2{n_{eff}}{T_f} \text{。}$

 ${\lambda _s} = \frac{1}{k}{n_{eff}}(\varepsilon ,{T_f})\Lambda (\varepsilon ,{T_f}) \text{。}$

 $\Delta {\lambda _s} = 2\Lambda (\varepsilon ,{T_f}) \cdot 2{n_{eff}}(\varepsilon ,{T_f})\left[ {\frac{{\partial \Lambda }}{{\partial \varepsilon }}\Delta \varepsilon + \frac{{\partial \Lambda }}{{\partial {T_f}}}\Delta {T_f}} \right] \text{，}$

 $\Delta {\lambda _B} = \left\{ {1 - \frac{{n_{eff}^2}}{2}\left[ {{P_2} - v\left( {{P_1} + {P_2}} \right)} \right]} \right\} + {\lambda _s} \text{。}$

 ${\delta _t} = \sqrt {\frac{{n_{eff}^2}}{2}\left[ {{P_2} - v\left( {{P_1} + {P_2}} \right)} \right]} \text{，}$

 ${L_t} = \frac{{{m_B}}}{{{m_A}}}100{\text{%}} \text{。}$

 图 3 光纤光栅传感器的灵敏度和误差特性曲线 Fig. 3 Sensitivity and error characteristic curve of fiber grating sensor
2 船舶应力测量和相应技术的结构可靠性监测系统设计 2.1 船舶结构可靠性监测系统的整体设计

 图 4 船舶结构可靠性监测系统的整体构成 Fig. 4 Overall composition of ship structure reliability monitoring system

1）应力采集功能

 图 5 船舶光纤光栅传感器的部署原理图 Fig. 5 Deployment schematic diagram of ship fiber grating sensor

2）缺陷检测功能

3）结构强度评估

4）报警功能

2.2 船舶结构应力可靠性监测系统的性能测试

 ${M_i}(t) = \sum\limits_{i = 1}^n {{\zeta _i}} {A_i}\cos \left( {{\omega _0}t + {\varepsilon _i} + {\xi _i}} \right) \text{。}$

 图 6 船舶局部结构的应力数据云图 Fig. 6 Stress data cloud diagram of local structure of ship
3 结　论

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