Analysis On Hull Girder Ultimate Strength And Residual Strength Of Damaged Ship By CSR

Ultimate longitudinal Strength of Ship Hull is the maximum capacity that the hull resists until it totally collapses,with ultimate bending moment as its reference point . The analysis and calculation of Ultimate Strength of Ship Hull is one of the basic tasks of the ship structural design, it is also an important indicator of the ship capacity.This paper mainly analyses the various kinds of buckling modes that hull girder stiffened plate under compression, and briefly lists the various stress-strain relationships given in specifications, that provides theoretical basis for the software. In the calculation process of the hull girder ultimate longitudinal strength, the nonlinear effects of the material and geometric should not be neglected, if still using the traditional method to analyses hull girder ultimate strength, it can not meet the situation of the real hull simulation. Therefore, the progressive failure analysis method is used in this paper, and using an artificial way to set the load on the hull girder cross-section until it damages , until the ultimate value obtained. Under the developing environment of VB, the software with simple interface and easy data input is designed, which greatly improved the calculation efficiency, and ensured its accuracy.The unlinear finite element software is another very effective method on calculating the ultimate longitudinal strength of hull girder. Nowadays ANSYS, MARC, MSC / NASTRAN, ABAQUS,and ADINA are widely used. Unlinear finite element software can also obtain accurate values of ultimate strength, if we can simulate the real situation of the structure reasonably. This paper, based on Prtran's model, Nishihara's box beams and a large selected of Bulk are calculated in the Marc's arc-length method, and comes out the data close to the results of the software in the paper. In the paper, according to assessment standard, calculation model and calculation methods on the damaged hull girder residual strength in standard ABS SafeHull, and based on original whole ship, the damaged ship is simulated by cutting units, then to calculate the residual ultimate strength. As the damaged hull girder is in a very situation, it would have some angle of roll, so when the neutral axis is adjusted, we should consider not only the translation but also the angle of rotation.Finally, this paper develop a software to calculate ultimate strength and the residual ultimate strength of hull girder which base on the progressive method. Compare with the value given by many scholars and the finite element values, the data calculated by the software in this paper is accurate. which can be applied easily in calculation and verification of hull girder ultimate strength.