Research On Three-Dimensional Parametric Design System Of Sheet Metal

Due to the metal sheet with easy molding, low cost, light weight and other unique advantages, the application of sheet metal products is more and more widely. In design and production of sheet metal parts, Sheet metal unfolding and layout are very important link. In order to improve the processing quality and production efficiency of sheet metal, worker must quickly and accurately calculate and draw the diagram of sheet metal parts. As a result, more and more scholars study method of sheet metal parts. In the traditional sheet metal parts production, sheet metal unfolding drawing method is usually used mapping method. In this process, graphic drawing is often dependent on the worker’s practical experience, come out of the great error in the expansion plan, which greatly reduces the production efficiency, and increase the cost. With the development of economy, the improvement of productivity and product update cycle shorter, Sheet metal of the traditional mode of production has can’t meet the competitive market. With the rapidly maturing of computer technology, using computer to replace artificial to complete has become the research hotpots of sheet metal parts, and CAD technology arises at the historic moment, he not only greatly improve the production efficiency, and ensure the accuracy of the graphics, improve the product quality. So it has great significance and application value that is researching on3D parametric design and unfolding of sheet-metal part.In this paper, three-dimensional model of sheet-metal parts is build by using vc++and based on the Open CASCADE geometric kernel, realizing3D parametric design. To different sheet metal parts, the corresponding mathematical model is set up for automatic unfolding, and spreading is mapped. The geometrical model of the Open CASCADE is an Open source kernel; based on it we can quickly develop3D CAD software. Open CASCADE not only provides powerful modeling function, and the application based on it avoid the commercial disputes. First of all, based on the OCAF generation wizard of Open CASCADE, we can generate application framework in vc++and complete the entire application architecture. Then, editing preferences dialog box by resource editor of vc++to, the user can through the dialog box controls the size of the metal sheet parameters. After get the size of the sheet metal parts, dispatching the model classes of Open CASCADE, three-dimensional model of sheet-metal part can be Build, and the3D model is loaded into the three dimensional environment, according to realize the interactive operation. Establishing mathematical model of developable surface sheet metal pieces, and using vc++write a mathematical function, according to user input, we can expand the model and realize the three-dimensional display of the expansion plan. This thesis integrates the exhibition of undeveloped surface so that the function of the system is more complete and powerful. Based on the Open CASCADE building3D model, through the vc++realizing3D parametric design and unfolding of sheet-metal part, the whole system is simple-operation and strong.