論文
プレス成形解析の材料流入予測精度の向上のための数値ドロービード特性計算手法
2018 年 59 巻 689 号 p. 107-113
詳細
2018 年 59 巻 689 号 p. 107-113
The numerical simulations of sheet metal forming are used practically in production preparation for automotive parts. Breakage and wrinkles are evaluated in most of the sheet metal forming by FEM analysis. The wrinkles are controlled by the restraining force with drawbeads. If the force is too large, a breakage occurs. Thus, the adjustment of the drawbeads are important in deforming the sheet metal without defects. The drawbead size is much smaller in comparison with the whole of automotive panels. If the whole panel is divided into finite elements with the mesh sizes corresponding to the shape of the drawbeads, the analysis takes several days. Therefore, the FE models of drawbead parts in the panels are normally omitted and drawbead force is given as the boundary condition, instead. A new calculation method of drawbead properties, in which a material and friction models conforming to the actual phenomenon were implemented, was proposed to improve the accuracy of sheet metal forming analysis. The difference between the predicted drawbead forces and the experimental values has been decreased to less than 10% at maximum. As a result of the application of these values to the calculation of forming an actual panel and a comparison with experimental results, the validity of the proposed method was verified.
