Research On Key Techniques Of Unfolding And Optional Nesting System Of Sheet Metal Parts

The sheet-metal components accounts for a great proportion in the Mechanical Products. There are more and more sheet-metal equipment is used in industry and our daily life. In the traditional mode of production, all works about the spread out drawing and nesting are performed manually. In this way, the design of productions are labor-intensive operation. It will take a lot of time. In recent years, with the development of computer technology, traditional mode of production is faced with a rigorous challenge. So the establishment of CAD system for sheet-metal products is necessary and meaningful.In this thesis, a new method of spread out drawing was put forward, on the base of summing-up and analysis of the traditional way. The method was presented to develop the system structure, system model, design method and realizing process of loft system for blank development of sheet metal components by using object-oriented techniques, parametric techniques,3D solid modeling techniques. With this method, we can draw the sheet metal deployment extremely efficient.A thorough study is made on the theory and techniques for optimum Layout of the sheet-metal. The preparation knowledge and the key steps to nest the sheet-metal structural member is discussed in detail in this thesis. To solve the problem of two-dimensional irregular layout, The genetic algorithm is applied in this paper. The irregular parts are changed into rectangular pieces by the using of minimum envelop rectangular. The result is shown by the Lowest-Horizontal-Line algorithm and is proved to be effective with the instance. The result shows that this algorithm can effectively shorten the time and improve the precision.