Aid Design Die of Auto-Body Using Numerical Simulation of 3-D Sheet Metal Forming Processes

It has been well applied in automotive manufacture of China about the technology of the numerical simulation of 3-D sheet metal forming processes during the recent years. Besides helping tool designers and artificers find optimal shapes of technical surface on the die, DYNAFORM is used in the early stages of the auto-body to work over the formability of various parts. In addition to the stamping process, the new forming technologies can be analyzed with DYNAFORM to find more efficient methods and optimal processing parameters for parts of the auto-body. The paper discussed how DYNAFORM is used to select a critical part in my plant and demonstrated how numerical simulation can reduce the developing time and costs of tools. For example, the formability analysis for the drawing die of the inside rear door on the car was performed using the numerical simulation of 3-D sheet metal forming processes. It is well known that the occurrences of both fracture and wrinkle were the two encountered difficulties in the stamping process. The numerical simulation was performed to analyze the metal-flow that caused the fracture and wrinkle on the draw-bead and it also acted to analyze the change of the blank’s outline that could bring up the fracture or wrinkle. The strain distributions were obtained from the numerical simulations and were also used in conjunction with the forming limit diagram to predict the onset of the fracture. The effect of blank-holder pressure and friction on the occurrence of the fracture and wrinkle was researched. To prevent the formation of the fracture and wrinkle, according to the above formability analysis of the numerical simulation, an optimum shape of the technical surface, the draw-bead distribution and sizes on the drawing die surface and the blank’s outline were finally determined.