A car or a truck contains a lot of sheet metal product (over 300 parts). In general, these parts are manufactured by a deep drawing process. However, during the last decade, a new production process with high potential is increasingly used to manufacture these sheet metal parts. This process is called hydroforming

In the hydroforming process parts are formed using a rigid die and a fluid under high hydrostatic pressure. It is used for the forming of tubular parts and flat sheets. In tube forming a pressure is applied in the interior of the tube and often a mechanical compressive force is exerted in the axial direction (end feeding). The combination of compressive axial stresses and circumferential tensile stresses facilitates the deformation up to high strains because necking is postponed by the axial compression. As a result, the hydroforming process offers the ability to manufacture products with very complex shapes which entails a high styling potential for product designers. Examples of automotive product, fabricated by tube hydroforming are roof rails, engine cradles and exhaust manifolds.


During Hydroforming many failures like wrinkling, buckling, folding back and bursting are frequently experienced. To investigate these failure mechanisms, several test geometries are defined, such as the free expansion test. The finite element method is used to validate the experimental results of the test geometries. Then, the validated model will be used to identify the typical failures modes that can occur during the hydroforming of a T-Piece and other related hydroforming products. After identifying the failure modes a true understanding of the failure mechanism can be studied. This understanding should result in potential solutions of hydroforming failures.

When the quality of the hydroforming is good enough, simulations can be used as a tool to check the manufacturability (robustness) and geometry of the desired part. To be able to achieve an optimal process, several geometric and parameter variations like end feeding must be investigated. Currently, this requires a lot of expensive and time-consuming manual work, based on experience. Due to the use of new materials and production processes, it becomes more and more difficult to find the optimum process settings. Therefore there is a strong need for an algorithm which is able to find the optimum settings for sheet forming processes. Nowadays, research on this topic is in full swing.

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