Comparison Of Direct Assessment Method Between Oil Tankers And Bulk Carriers

Common Structural Rules for Bulk Carriers (hereinafter referred to as CSR BC) and Common Structural Rules for Double Hull Oil Tankers (hereinafter referred to as CSR TANKER) have been published for three years, the user felt inconvenience due to some differences between the two rules despite of the advance of CSR. Thus, International Association of Classification Societies asks for coordinating and harmonizing CSR BC and CSR TANKER. Direct yield and buckling strength assessment methods of two rules were compared in this paper, which provided a reference for harmonizing two rules. The main contents including:1) Direct yield and buckling strength assessment methods and procedure of the two rules were systematically summarized.2) Yield strength assessment methods of two rules were compared. Including: finite element modeling, loads and loading conditions, loads adjustment methods, boundary conditions, yield assessment criteria, fine mesh model and assessment criteria, buckling conditions and acceptance criteria.3) Combined with the stability of plate theory, buckling factor of CSR BC is derived; buckling theoretical basis of CSR BC is explained. Reduction factor of CSR BC is derived by using concept of effective width, the method which taking effect of post-buckling into account is proved. 4) The theoretical background of the CSR TANKER advanced buckling analysis procedure—PULS is studied. And the method which takes effect of non-linear factors into account is illustrated by researching on three kinds of basic plate element.5) Four projects for unifying rigid-link of two rules are presented, a bulk carrier and an oil tanker is calculated. This work provided a reference for the project of harmonizing two rules.