Parametric Design And Structure Analysis Of Working Ship

Working ship has a relatively fixed structure, which generally not more complex linear,so it is feasible to apply parametric design technology in the design of this ship.The structural design of the working ship works from the programme concept,drawings expression, performance analysis to determine the final programme is a relatively cumbersome and complex process. The traditional design methods with low efficiency, has been seriously affected the progress of ship design. The parametric CAD research is the hot in the field of contemporary design, which is the way to solve the problem of the above, so it has very good practical significance and engineering application prospects.During the structure design of working ship, AutoCAD is a software with powerful graphics rendering functions, Many of these functions provides great convenience for us to do structure design work of working ship, and make drawing more convenient.However, it is not specifically designed for the structural design of the ship, directly applying it to engineering design of the ship structure still has a great inconvenience, small change of the profile will lead to a corresponding change in the structure ,These changes required modifying Bit by bit,cumbersome and time-consuming, and error-prone. In view of this in order to make better use of it to the structural design of ship, and ease of use, secondary development based on the exist sofware must be carried out to complete the parametric design of ship structural plan.The size of the previous structure of the ship are mainly based on the construction standards that survey department established following a long-term accumulated experience. So long as ships' main dimensions have been determined, we may carry on the computation based on the standards to etermine various components' size.Generally that can also guarantee the strength of ships' structure, but actually is not necessarily reasonable, also uncertain economic. The late 1970s, due to the large scale of the ship as well as the development of the new ship type, classification societies all over the world are looking for both advanced and reliable scientific and rational design and calibration methods, and so direct calculation method of the strength of the ships' structure was proposed, all classification societies have developed guides or guide for a direct calculation of the structural strength.Through the finite element analysis method and software, we may use the three-dimensional model and direct calculation method of the hull structure strength to calculate longitudinal strength and the partial strength, and the speed and the computation precision enhances greatly. Through the design stage's simulation analysis, the designer may judge the structural design to be whether reasonable, thus avoids the significant safety incident's occurrence.The re-development in the AutoCAD software's platform to realize the ship structure's parametric design is firstly carried out in this article.And the author have understood the AutoCAD ActiveX technology and the AutoCAD object model as well as the commonly used step of developing application procedure with VBA, and realized the structure parametric design of some Semi-submersible ship in the AutoCAD2004 platform through the compilation of massive procedures, realized the ship structure's dimension control, completed the automatic plan and output of drawings. Then the structure drawing created by the programme was induct the ANSYS software to carry on the finite element analysis, completed the appraisal and the examination to judge the structural design to be whether reasonable, whether the structural strength does satisfy the code requirement. Two analysis methods has been used in the article ,namely the frame model as well as the section model, and have carried on the analysis and the comparison of two kind of models.The research carried on in the paper , effectively reduced that long process from the plan idea, the blueprint expression, the performance analysis to the final plan determined, sped up the working ships' design progress, raised the design efficiency and the flexibility, and made the appraisal to structural design's rationality.