Abstract: Fluid-cell forming process (FFP) suffers seriously from the product quality problem due to springback. As the most effective method to solve the problem, springback compensation technology with FEM requires a long period for numerical analysis, which limits the method in practical use. A new tool design method with springback compensation is proposed for FFP, where the tool surface is constructed and then adjusted directly without numerical simulation. Based on discussion of springback rules for curved flanges, a springback distribution function is devised to predict springback angles of curved flanges by using geometrical parameters. With the displacement adjustment method, the springback angles are mapped to nodal adjusting vectors of the die mesh and the optimized die is obtained. The above procedures are applied on a real fuselage flange part and the result shows this method is valid.

Key words: Flange, Fluid-cell forming, Sheet metal forming, Springback compensation, Tool surface design