Forming limit of sheet metal in cylindrical deep drawing with a conical die

Abstract It is well-known that the use of a conical die in cylindrical deep drawing can enhance the formability compared with conventional process. The most commonly observed failure mode in the process is fracture near the punch corner or wrinkling in the flange region. In order to obtain the limiting drawing ratio (LDR), a cylindrical deep drawing including only the conical die and flat punch is discussed based on numerical simulation in the paper. A finite element model for the deep drawing with a conical die is developed, and the accuracy of the model is verified by experiments results. The investigation shows that in the cylindrical deep drawing with a conical die, the types of failure above, which can obtain for thinner sheet materials, are obviously related to the sheet thickness and the conical angle, and the optimum conical angle is also found.