A Study on Fatigue Analysis for 306K Crude Oil Tanker based on Li's Approach

Abstract

The fatigue problem of the metal as hull material is a permanent hot issue. The fatigue phenomena at ship hull mostly occur suddenly, which always cause huge casualties and economic losses. At the same time, fatigue is also an important failure form on ship structure. Since the last decades, with the widely usage of high-tensile steel (HTS) in ship structure and the ship size is becoming larger and great attentions have been paid on the problem that how to assess the fatigue strength of ship structures reasonably. A growing number of fatigue incidents in local structural details especially when using HTS steel have demonstrated that a more direct control of fatigue is required. In order to meet the needs for designing, building and testing of modern ships, IACS (International Association of Classification Societies) organized the major classification societies all over the world to compile the CSR (Common Structural Rules) [1], which has introduced since April 1st, 2006. This paper presents the study of method in fatigue life assessment based on Li’s approach [2] by using MSC. Fatigue. Two methods are applied and discussed in the fatigue life assessment of 306K crude oil tanker based on the CSR as companions of Li’s approach. The details of the methods from the CSR and the Li’s approach have been illustrated in the other following chapters. From the study and comparison with two methods, it can be concluded that the Li’s approach have several advantages such as: 1) wide application of different structural details; 2) easily for using; 3) accurate results and so on. Finally, the Li’s approach can be proved to be feasible in assessment of ship’s fatigue life by comparing the results of the methods mentioned above.