Research On Program System For Calculating Probabilistic Damage Stability And Residual Longitudinal Strength Of A Deck Cargo Ship

A ship may be damaged by stranded or collision. In order to avoid the damaged shipsinking or a further pollution of the marine environment, it needs not only to calculate aship’s damage stability, but also to have an understanding and evaluating of the residualstrength of damaged ships.The calculation methods of ship damaged stability divided into deterministic damageresearch and probabilistic damage research, along with the development of shipbuildingindustry and scientificalness, the probabilistic damaged research has gradually replaced thedeterministic method to get more attention of people’. For the study of residual longitudinalstrength, most scholars discussed it based on the deterministic damage, however, this paperwill based on probabilistic damage.This paper studies on a96m deck cargo ship and calculates its probabilistic damagestability, which according to the relevant requirements of SOLAS regulations(2009). Theresults meet its requirements: the attained subdivision index A should greater than therequired subdivision index R. Then analyses and checks on the longitudinal strength ofdamaged ship based on the probabilistic damage combinations.In this paper, we used a friendly software Visual Basic that launched by the MicrosoftCorp to develop the calculating and checking system to achieve the research above. Thesystem includes the common function module such as input, computation, output and help.The system has achieved the ship modeling, subdivision, loading, calculation and a series offunction. The system has obtained maximum bending moment envelope and maximumshear envelope based on the hundreds of probabilistic damaged combinations. During theanalysis of residual strength, the incompleted structure profile that cause by damage isconsidered. So the minimum section modulus can be calculated, thus we got the allowedmaximum extent of damage.The system also calls NAPA to achieve some function; and links with the Accessdatabase to store the ship data; then use Excel to implement comparison and analysis with alarge number of data by its good interface. This function reduces labor and improves workefficiency. The system has a certain practicality and engineering significance.