Root Causes of Thin-Plate Buckling Damage at the Aft-End in Crude Oil Tanker and Verification through Buckling Analysis

Abstract

For large ships and offshore vessels, structural safety is verified through whole-ship analysis using commercial software. In the case of general oil tankers, classification rules for structural strength evaluation are uniformly applied. Structural strength evaluation is mainly divided into the cargo hold, fore-end, and aft-end parts. For the structural design of a cargo ship, it is important to calculate the design load and determine the thickness and size of the structural member. Structural FEA (Finite Element Analysis) is performed on only the cargo hold range as recommended by the CSR (Common Structure Rule). There is no FE analysis recommendation for either the aft- or the fore-end area. Therefore, structural safety is carried out based on existing design experience and engineer judgment. With previous approaches, it is difficult to clarify the safety of the aft-end part according to external loads such as hull girder load and local pressure. Recently, local buckling damage cases have investigated the aft-end of the shuttle tanker. Although this is a good example, it can be recognized that it is necessary to improve the accuracy of prediction when estimating the structural safety at the aft-end part. In this study, a novel FE-based evaluation methodology about buckling damage is proposed. In order to conduct a structural strength verification based on FE analysis modeling, reasonable solutions for load conditions, boundary conditions, modeling methods, and evaluation criteria are presented. This result is expected to be helpful in examining the structural strength of the aft-end part of similar carriers in the future.