Papers by Keyword: Blank Design

Abstract: Blank shape design is the prerequisite and foundation of optimization for the closed forming the high-neck flange. This paper obtained the design formulas of blank size with analyzing the mathematical model of flank blank based on the principle of volume invariably during the rolling process.The blank of a special flange was designed by this method which was validated by the numerical simulation under the DEFORM software. The results indicate that the product is qualified with the blank shape based on this method. These research conclusions can provide scientific basis for forming the high-neck flange with rolling method.

Abstract: A novel hybrid method is proposed in the paper, which is an assistant tool for product designers to estimate springback in sheet metal forming process at the preliminary design stage. In the hybrid method, the forming results are obtained firstly by an inverse finite element approach (IA) with a membrance element. The thickness strain and stress can be calculated according to the approximate curvature radius of the discrete meshes. Then, a rotation-free shell element is employed, with only three displacements at the corner nodes of the element, to calculate the springback. To verify the accuracy and efficiency of the hybrid method, the numerical results of the hybrid method on two benchmark tests are compared with experimental results.

Abstract: At the early stage of product design, the information about mould, blank and boundary condition are not definite. It is difficult to calculate with incremental method. For solving this problem, one-step finite element method(FEM) was put forward in recent years. It starts from product shape, takes it as the middle plane of formed part, disperses it and determines the location of nodes in initial blank at certain boundary conditions with finite element method. Then the corresponding blank shape can be obtained by one-step FEM. In this paper it is discussed that the basic theory of one-step FEM and the research of the key technology. And it is simulated the pressing of auto panel with one-step FEM. It is put forward that the final part should consider the effect of the technology. Through comparing one-step FEM with incremental method, it is showed that one-step FEM could calculate rapidly and had some credibility. It was suitable to evaluate the formability at the early stage of product design.

Abstract: A convolute cut-edge design is performed using FEM (Finite Element Method) for a single step cup drawing operation in order to produce an earless cup profile. Mini-die drawing based on a circular blank shape is initially carried out in order to verify the earing prediction of the Yld2004 anisotropic model (Barlat et al. [1]) for a body stock material. Realistic cup geometry is then employed to design a non-circular convolute edge shape. An iterative procedure based on finite element method is initially used to design a convolute shape for an earless target cup height. A constant strain method is suggested to obtain a new convolute prediction for the next iteration from the current solution. It is proven that Yld2004 model is accurate to predict the anisotropy of the material.