大型油船和集装箱船静水弯矩的统计特性研究

A STUDY ON THE STATISTICAL CHARACTERISTICS OF THE STLL-WATER BENDING MOMENT OF CONTAINERSHIPS AND LARGE OIL TANKERS

本文介绍了国内外静水弯矩的研究现状，对Soares和Moan的经验回归公式进行了详细讨论，发现不同的研究人员对静水弯矩统计特征的认识存在相当大的差异。文中对静水弯矩均值和变异系数对船舶总纵强度安全指数的敏感度进行了分析，发现均值比变异系数更加重要。在分析和比较的基础上，根据简单可靠的原则，对集装箱船和油船的静水弯矩统计特征计算提出了如下建议：集装箱船，Cov=0．30；油船，满载（中垂）时，Cov＝0．4，压载（中拱）时，Cov=0．70。

In recent years, much attention has been focused on the determination of the statistical characteristics of still-water load effects. In this paper, a detailed review is first given on the state-of-the-art of still-water load effects. Then the empirical regression formulas given by Soares and Moan are discussed. It is found that a great difference exists among researchers on the statistical characteristics of still-water load effects. Therefore, a sensitivity analysis is carried out to investigate the respective influences of the mean value and the coefficient of variation of the still-water bending moment on the ultimate longitudinal strength of ships. Based on the comparison and the reliability analysis, the following suggestions are made in determining the statistical characteristics of still-water load effects according to the simple and reliable principle: for containerships: M/M. = O. 7O, Cov =O. 3O; for oil tankers in ballast condition: Cov = 0. 70; for oil tankers infull-load condition: Cov = 0. 40.