| With the increasing of vehicle safety and light weight requirements, the advanced high strength steels (HSS) and aluminum-magnesium alloys are widely used. Springback is the most common defect in sheet metal forming. Furthermore, there are many factors affecting springback, the finite element method and numerical simulation technology cannot accurately predict the defect. There is not a quick resolution mechanism for springback from product design to stamp and tryout of auto parts. Therefore, looking for a quick solution to improve the dimensional accuracy of AHSS auto parts is the most important research topics in sheet metal forming.This paper is supported by the grant form Major National Science and Technology Project (No.2010ZX04014-072) and National Natural Science Foundation of China (No.50905066). Process control springback method by experimental, full process refinement springback simulation, geometric springback compensation algorithm and system, fast simulation method based on product were conducted in-depth research. Based on the above findings, an integrated system was developed, which is the first system oriented product development full process for simultaneous engineering.In order to study the rules of process control springback method for AHSS parts, the experimental drawing die has been designed and made based on the S_Rail part of the Numisheet1996. The effect of process parameters to AHSS and aluminum alloys was researched based on servo press, and the process control springback method with servo forming technology was established for AHSS and aluminum alloys sheet metal stamping. The experimental results shows that the blank extrusion deformation in the thickness direction under the extreme pressure can reduce the springback effectively. Conversely, holding time and forming speed have not effect on the springback. The results shows that the process parameters can only reduce the springback, but not eliminate the springback thoroughly.The precision of springback simulation is a current major problem of numerical simulation. An eight-node solid shell element model-MHSSS was proposed based on the experiment results of AHSS S_Rail with extreme pressure and negative clearance, which can accurately simulate the extrusion deformation in the thickness direction. Furthermore, the full process precise springback simulation method based on precise digital dieface was proposed, and the foundation of precise digital dieface was CAD platform, including real drawbead model, real extreme pressure and real dieface open process. The forming and springback simulation accuracy can be improved by the solid shell element model and full process precise simulation.Springback simulation results can not be directly compensated on the precise digital mold dieface. In order to solve this difficult problem, a new quick geometrical springback compensation algorithm based on UV curves was proposed for AHSS auto parts, withing the research of structural characteristics and springback compensation ideas of automotive structural parts. In order to reduce the time and cost of the die manufacturing, this algorithm was seamlessly integrated into the CATIA platform. The compensation dieface was reconstructed by this algorithm a can be directly applied to actual NC programming.In order to control springback at the stage of product design, fast simulation method with selective substructure based on product and fast incremental simulation method with intermediate process based on product ware proposed for stamping simultaneous engineering. The local areas and intermediate process of the product can be accurately simulated by fast simulation method. Finally, an integrationed CAD/CAE/CAM system was developed for the full process of automotive stamping products development, which provide; software support for the stamping simultaneous engineering. |
