Improving stretch forming of complex shapes
Driven by a desire for weight reduction, the use of aluminum sheet is receiving increasing consideration by industry. Apart from the aerospace industry, where aluminum is the material of choice for most parts, interest from the automotive industry is also growing, for example, for inner and outer body panels. The formability of aluminum is in general less than for steel. Therefore, in many industrial forming processes using aluminum, the mechanical loading is combined with a thermal component (like annealing) between subsequent deformation steps or deformation at elevated temperatures.
Goal of this research was to replace trail and error based production technology of complex-shaped saddle skins, such as part of the wash or tail to fuselage fairings, by advanced methods to obtain the correct product and related tooling. Two research topics were defined: to investigate the use of FInite Element Modelling in the stretch forming process and to make use of correct material models.
Through this research:
• The number of forming steps could be reduced from 9 to 6.
• The manufacturing time was reduced by 50%.
• Scrap went down from 50% to 10%.