A Case Study of Drawbead Design of a Deep Drawn Rectangular Part Using FEM

The deep drawing manufacturing process of sheet metal parts with complex shape has increased recently in applications such as in the automotive industry and the household appliances. The trial and error methods commonly used in defining the process parameters, cause high costs and large development times. The computer assisted analysis and simulations are being used more frequently to reduce the cost and development time of a product. The process parameters can be modified and evaluated using these computer simulations before the production is carried out. Therefore the defects of a part can be identified and eliminated, if possible, without the need of the traditional trial and error methods. This paper presents a case study of an industrial component that presented defects (wrinkles at the corners) in its deep drawing process. To eliminate these defects a drawbead was proposed and its optimal location was established using an optimization procedure based on finite element method (FEM). The FEM simulations were validated by measuring the thickness of the fabricated part. To evaluate the elimination of the wrinkle, the thickness of the sheet metal at the critical area was measured in the FEM simulation and compared with the thickness profile before and after the addition of the drawbeads. The results have shown that the design strategy based on FEM can be effectively used as a design tool to eliminate part defects in rectangular deep drawing process.