Study On Direct Calculation Of Yield Strength And Buckling Strength Of Bulk Carrier Based On Harmonised Common Structural Rules

In view of the frequent occurrence of the sea damage pollution accident due to the hull structure defects and the improvement on the classification rules system required by the modern ship design and construction, promoting IMO into hull structure standards setting, IMO GBS emerges as the times require. Also to eliminate ship safety level differences induced by the inconsistent of the classifications rules intended to inhibit the low standard ship construction and to comply with firmness and durable requirements on ship design, IACS established bulk carrier and oil tanker Common Structural Rules, respectively. And this was formally implemented in April1st,2006. These two specifications unified the standards of the two type of ships in the global scope.However, because of the two drafting from two different project teams and their hasty development process it caused ship industry disputes on the incompatibility of the calculation methods of wave load, finite element, bulking strength, fatigue strength and safety criteria definition. Therefore, IACS generalized by general treatment on the inconsistent content of Common Structural Rules to establish Harmonized Common Structural Rules in the new frame and complemented study content to satisfy IMO GBS requirements intended to pass the IMO GBS audit and be accepted by the industry field.With the development of modern computer technology, the finite element analysis on the hull structure has become an indispensable part of ship structure design. In this paper, the study of finite element yield strength and buckling strength direct calculation method has been carried out based on the first drafting edition. The main contents are as follows:First, the theoretical basis of strength criteria is illustrated according to HCSR yield direct calculation. And the main content and basic process of finite element direct calculation is introduced in detail, including selection and establishment of finite element model, the determination of load cases, the calculation of design load, the application of boundary conditions, the adjustments of the hull girder load and the strength analysis criteria.Secondly, the failure mode of stiffened plate buckling has been illustrated and stiffened plate buckling strength has been studied. Then the buckling assessment method and the limit state equation and buckling strength criteria is specified based on the finite element direct calculation according to HCSR buckling strength direct calculation. Finally, the real ship experiment has been done with a35000DWT bulk carrier as an example. What’s more, the HCSR finite element direct calculation method has been implemented in the whole analysis process of the yield and buckling strength assessment. In addition the influence of HCSR yield and buckling direct calculation on the bulk carrier which has satisfied CSR requirements is preliminary discussed with the analysis results. And this has provided the specifications suggestions for futher adjustments.