The Analysis On Ultimate Strength Of Large Bulk Carrier

In the modern ship construction design research realm, people pay more and more attention to the ultimate strength of ship hull girders. This is because that the perfect construction design is closely associated with the true strength store of the ship girders.With the studying on and researching failure mechanism of the hull, when researching the longitudinal strength of ship hulls, the failure modes of buckling, yielding and their combination, as well as the non-linear interactions between the pressed structural members should be considered.There are three main methods by far, nonlinear finite element method, idealized structural unit method and progressive collapse analysis method. This article use nonlinear finite element method, considering the non-linearity both in material properties and in geometry of deformations. The workload involved in this method is very heavy and the method need many resource but relative accurate.With great developments in modern mechanics, computational mathematics and computer technology in hardware and software, finite element analysis has made rapid progress in both theory and computational technology. More and more general-purpose or specialized programs have been in use, costs on performing FEA are reduced shapely. Currently, FEA and its programs have become the standard tool for engineering design.Some calculation indicated, general-purpose programs can forecast load carrying capacity of a ship's hull accurately if we take sufficiently into account every load and boundary combination, structure imperfections and initial stresses, together with geometric and material non-linearity.In this article, we have analyzed the ultimate strength of Faulkner's stiffened steel plate, the typical modal of Nishihara hull girder and large bulk carrier by using the general-purpose programs. We have discussed the influence of ultimate strength of the Nishihara hull girder with imperfection in the decktogether with material and geometric non-linearity. By using the general-purpose programs MSC/MARC we have gained some detailed results to know how to improve the precision and how to consider the imperfection of a ship. Through comparing FEA results with foregoing calculation results, we put forward some suggestions, which may be useful for future FEA.