Mathematical Models For Computer Draw About Nodes Of Jackets And Program Design

With the quick development of computer technology, computer aided design is widely applied to all kinds of fields. The intersectional pipe fittings are used in the jackets of the sea platform directly. For the development of intersecting curve, its traditional method is the geometry drawing method, which is not only complex but also time taking, in addition, precision of the developed curve are low. With the second-development of AutoCAD, the CAD (computer aided design) of development of intersectional curve between pipes with intersectional axes and distances between axes in both ends of pipes is established in this program, which is visible and parametric. The main contents covered by this paper are as follows:1. Base on the theory of analytical spatial geometry, this paper deduces mathematical models for development of intersectional curve between pipes with intersectional axes and distances between axes in both ends of pipes.2. On the platform AutoCAD2004, the code of this system is programmed with Visual Lisp. This software can develop the intersecting curve between pipes with intersectional axes and distances between axes in both ends of pipes. By this software, the coordinates of discrete points on the developed curve are calculated; further, these points are connected continuously so as to obtain a developed intersecting curve, which is up to the required precision. While the intersecting curve is drawn, the relevant curve data is generated at the same time.3. The interface between computer and operator is developed with drop menu and function of catch of AutoCAD, map. In this way, data can be input easily and visually.4. Data output provide ruler of plate for steel plate, improve the efficiency of using steel plate.On the basis of practice, this program is proved to have such features as parametric development drawing, fast drawing generation, high precision developed intersecting curves, easy operation and extensive application. According to the generated curves, the digital controlled cutter can produce accurate sheet metal parts efficiently. What is more, the sheet-metal drawing can be generated and ruler of plate be provided so as to facilitate the production.