Buckling Assessment Of Hull Shells Based On Common Structural Rules

The ship's hull is a thin-walled box girder structure composed of stiffened panels. Buckling and plastic collapse of the stiffened panels which is composed of the deck, bottom plating and side shell easily causes the overall failure of a ship hull girder. Therefore, the analysis of buckling strength of ship panels in deck, bottom, and side shells is very important and necessary for the safety assessment of ship structure. Until now, the major classification societies have already released their assessment notes before "Common Structural Rules" being specified. As there are different specifications with varying classification societies, safety criterions of The Classification Societies exist lots of differences. For that season, IACS weaved a new regulation called "Common Structural Rules for Double Hull Oil Tankers" which is called " Common Rules " for short in order to unify the evaluation flow.The paper describes basic methods and analytical approach of buckling strength assessment of oil tank structure in detail, basing on technical specifications of buckling strength in " Common Rules " . The author also compares " Common Rules " with "Guide of Structural Direct Calculation and Analysis for Oil Tankers"(for short, it is called "Analytical Guide") in the analysis of buckling strength, calculates FEM which undertake respective loads and compares two results of buckling strength analysis. Its main content is as follows:The author emphasizes the significance and purpose of the research in buckling strength, and reviews the status in this field.According to the FEA model of 26,000DWT chemical oil tank based on "Analytical Guide", the distribution of the stresses of the model in specialized load cases is calculated. The structural strength of the ship is assessed. The buckling assessment of the main ship plating such as the deck, the bottom, the side shell, the inner shell, the longitudinal and transversal bulkhead is undertaken.According to the FEA model of 26,000DWT chemical oil tank based on "Common Rules", the distribution of the stresses of the model in specialized load cases is calculated. The structural strength of the ship is assessed. The buckling assessment of the main ship plating such as the deck, the bottom, the side shell, the inner shell, the longitudinal and transversal bulkhead is undertaken.