Path Generation And Simulation For Complex Surface Digital Incremental Forming

Fierce market competition demands that the manufacturing industry should shorten development cycle and decrease producing cost. The sheet metal incremental forming technique is a new technology, which can directly produce the product from CAD model rapidly and economically without any die. This technique, which is adapted for product development and small batch production, has many applications in the fields of aerospace, automobile and so on. The study on path generation and simulation for complex surface digital incremental forming in this paper is propitious to improve forming quality and accuracy, and has a great contribution to popularize the incremental forming technique. The main research comments are as follows:Firstly, the surface of the STL (Stereo Lithography) model was divided according to its formability so that the multi-pass forming can only be implemented on difficulty forming surface. Multi-pass forming tool path was generated by offsetting the last pass spiral path at the difficulty forming area. Secondly, a spiral tool path generation method with constant scallop height for sheet metal CNC incremental forming was proposed based on the STL triangular mesh model. The path interval computation with constant scallop height was researched after the normal curvature estimation of the STL triangular mesh model had been completed. The spiral tool path generation algorithm, that the next spiral path is automatically propagated from bottom to top by the spiral drive path which is generated by the polygon boundary of the model undersurface, was studied. At last, the sheet metal CNC incremental forming process was simulated by using ANSYS/LS-DYNA FEA software, aiming at the problems that the FEA software cannot read the NC code directly and that the long simulation time caused the low efficiency of path checking, the platform of simulation which had the ability of reading NC code and could simulate the process of sheet metal CNC incremental forming, was established based on the Z-map lattice model.The algorithm on path generation and simulation for complex surface digital incremental forming was realized in the Windows XP environment using Visual C++, OpenGL in this article. The case studies show that the proposed algorithm in this paper can accomplish the complex surface division and generation of multi-pass forming path, generation of spiral path with constant scallop height and dynamic simulation for sheet metal CNC incremental forming. The program runs stably and reliably.