Study On Methods Of Parametric Modeling Of Jack-up Platform Based On Catia

At present, 3d modeling of platform is usually designed in the traditional CAD system and its deficiency has been exposed gradually. First, designers can't build the model quickly according to its characteristic. On the other hand, the support design is insufficient in the design progress of products.In order to solve the above problems, this thesis researches parametric modeling system of Jack-up platform based on knowledge. The main research contents of the paper are as follows:1. Based on the relationship database, adopting production rule as knowledge representation, the method of designing of knowledge base is introduced and the rules of structural design of offshore Jack-ups platform is stored to knowledge base as knowledge source. On the basis of this, reasoning system was set up, and the final component parameters is got by basic parameters inference. So this system not only has the function of intelligent design but also can judge and check while modeling.2. According to structural characteristic of Jack-up, after its character was extracted, filtered and assorted, the parameter model is set up, then, constraint relations of characteristic parameters is built, especially of the geometric dimension and position parameters. At last full scale constraint of the model is established as well as dimension and characteristic driven is realized.3. During the phase of application program design, combined with system's logic model, using structural design method, the module structure of the application program is divided and designed. The second development of CATIA with Visual Basic is done and 3-dimension modeling of offshore platform is realized by means of parametric modeling based on characteristic. Furthermore, with the rule base of structural design, the system has the ability to judge and check while modeling.With the idea of parametic modeling, full scale dimension constraint model of Jack-up was built, and then only need to adjust some parameters, many kinds of models can be eatablished. This system is of great significance for reducing workloads of workers. Otherwise, with the rule base, all dimensions of the model can be checked without referring to rules.