Research On Ship Hull 3D Modeling And Calculation Of Ship Stability Based On The CATIA

Both in the process of ship design, construction and operation, the stability of ship is the key factor that generally paid high attention which is closely related to personnel and property safety of the ship and marine environmental protection and other aspects. The former calculation of ship stability is achieved in the way of numerical integration method. But the result of 2-D numerical calculation lacks sufficient precision because of the tedious input steps.Accurately constructing the ship model is not only the basic work of calculation of stability but also the basis of following ship design, so the accurate construction result of ship design is particularly important. With the development of computer technology, three-dimensional modeling commercial software continues to spring up. Accurately constructing the ship model in a high speed has been an important issue in ship design. CATIA V5, a three-dimensional software based on the Windows operating system, is widely employed in aviation on a leading position, while a little late start in shipbuilding industry. Still, it includes the specialized modules with strong 3-D modeling capability, such as ship structure, piping system, electrical and air duct design. CATIA smartly performs in 3-D curved surface design and effectively smoothes complex molded lines and curved surface. And it provides a secondary development interface which makes it easy for the related calculations of the shipping 3-D model.3D modeling is traditionally achieved by inputting point manually one by one which is complex to operate and error-prone. And the accuracy of following calculations of ship stability can't be ensured. In order to solve the above problems, this thesis mainly did the following researches:(1) Based on CATIA, this thesis studies the formation of 3D solid model for hull structure from wire-frame model and performs the second development by means of VB where the quick modeling of 3D curved surface solid ship model is achieved by accessing the data from Excel. This thesis also conducts necessary development on rapid ship subdivision in order to reduce the repetitive operation and simplify the modeling process providing the data geometrical model for the following stability calculation.(2) Based on the three-dimensional surface model, this thesis draws the ship hull molded frame line and calculates the flooding angle curve automatically based on the secondary development of CATIA, and the quality and efficiency of ship design are improved.(3)This thesis calculates hydrostatics based on 3D model and completed the related hydrostatic calculation in modular and procedural manner through 3D quick modeling. In this way, designers are free from the time-consumer and trivial process while saving considerable human and time costs.(4)A method of calculation is presented in this thesis to obtain the large angle stability through which the related commands can be quickly achieved in a automated, parameterized and visual way. This simple and practical system interface is easy to use and operate with good man-machine conversation capability. Users can quickly complete the calculation of ship stability through simple procedures to reduce the computing time and increase the efficiency accordingly reducing the costs and manpower.