Research On The Container Ship Intact Stability Based On The Second Generation Intact Stability Criteria

In recent years, with the rapid development of ship industry, container ship, with its low cost and high efficiency advantages is widely favored by ocean transportation industry, becoming an important part of shipping network. Container ship has loading characteristics of loading a lot of containers on deck and high center of gravity. Its KMT value is bigger than the general types. Therefore, the safety performance in the process of navigation is also becoming more and more attention. The ship stability study is one of the most important performances that make sure the safety of ship’s sailing. At the same time, it is also one of the tasks of ship inspection. At present, the study of stability is mainly about that ship in still water, however, in fact ship always sail in the waves. As a result, the task of developing new generation intact stability criteria is pressing. So the study of parametric roll and pure loss of stability is very necessary.The work of the article is to study the stability of container ship,The main contents are as follows:1) Using NAP A software to calculate container ship’s stability in the still water. This article mainly take five typical loading conditions to calculate.2) An study method of righting lever when ship sails in waves is presented. Based on three coordinate systems, When calculating the balance between gravity and buoyancy and the balance of trim, the intersection points of the boat and the wave are also calculated. Then, one more current method of calculating instantaneous wet surface and center of instantaneous wet surface is presented to calculate ship displacement of volume and center of buoyancy. Then, based on Froude-Krylov hypothesis, righting lever in waves are obtained. Using MATLAB software to develop responding calculation program and taking the container ship to calculate righting lever in waves. And then analyze the influence of the wave frequency, wave steep, wave direction angle and relative location of the ship and wave on the changes of stability. At the same time, the righting lever in calm water has carried on the comparison and analysis.3) Introducing the parametric roll criterion draft and pure loss of stability draft, then using MATLAB software to develop responding calculation program. And then taking the container ship to check the parametric roll criterion and pure loss of stability criterion in the four typical loading conditions.