The purpose of this research was to find manufacturing processing conditions that would prevent the occurrence of fractures in a sheet-metal bending product. The finite element code ABAQUS was used to analyze the tensile strain at the particular point where fractures frequently occur. First an optimal combination of factors was sought using the method of controlling parameters. The analysis showed that the three factors, r2, r4, and the coefficient of friction, which are typical controlling factors, cannot be used to reduce the tensile strain at the critical point efficiently. A preform design was then applied to solve the problem of fracturing. By using a two-step bending operation, we successfully moved the highest tensile strain away from the critical point and also reduced the magnitude of this strain.

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