FEA - Calculation of the Hydroforming Process with LS-DYNA

The automotive industry is constantly searching for product improvements concerning weight reduction and the need for corrosion resistance. Currently aluminium alloys are of special interest because of their low density of 2.76 g/cm3, and good corrosion resistance. The disadvantage of aluminium alloys is poor formability in comparison to steel. Therefore, new forming methods are demanded such as the “tube hydroforming” process, which has been reasonably successful in creating complex parts in aluminium alloys. This process involves the concurrent pressurization and axial compression of a tube, causing the material of the tube to flow into a die cavity, achieving the form of the final component shape. Lightweight and complex forms of aluminium components have been achieved successfully, when the process parameters are calculated and controlled accurately. Due to its various shaping and design possibilities, the hydroforming process has been used for more than 10 years in the automotive industry for the production of complex carrier structure units. The requirements e.g. the shaping possibilities, respectively, the design space of unit geometry, the expansion relationship, as well as the maximum plastic deformation possibility has risen constantly over that time. This requires ever larger efforts to fulfil these requirements under the compliance of fixed time and cost goals. The contents of this work are the task of the FEA- Simulation of the hydroforming process. It consists in a general feasibility study for the forming behaviour of the semi-finished product and/or the tools. Due to the complex connections of the process influence parameters the non- linear finite elements (LS-DYNA) offers the condition to fulfil these requirements, in particular regarding plausibility check, general feasibility as well as adjusting quality and tolerance field promises (formation of wrinkles, springback, form and position tolerances). A quality increase can additionally be derived accompanying the increase of manufacturing security for series production by the evaluation of the manufacturing simulation.