In a sheet metal forming process, fracture and wrinkle are the most difficult task in new parts launching. The variation in process condition generates the fracture and wrinkle fluctuation. The fracture and wrinkle are very sensitive to the process conditions, then the main effects of the design variables cannot be obtained from the standard mean analysis. Therefore, in order to minimize the fracture and wrinkle in parts of automobile, a special method to counterpart is required. In this study, a new design method to achieve the optimal in the sheet metal forming process is proposed. The effectiveness of the proposed methods is shown with an example of the parts of fracture and wrinkle.

The objective of this study is to predict the formability of sheet metal for the bladder press. The static implicit finite element method is applied effectively to analyze bladder forming processes using AutoForm software. The material used for forming analysis is AL2024, and the thickness of the plate is 1.6mm, 1.8mm and 2.0mm. Forming force is shown by 101.92kN～87.22kN. The result from the simulation analysis was applied to the bladder press system.