Numerical Simulation of Electrohydraulic Forming using Coupling of ALE and Lagrangian Elements

Electrohydraulic forming is a high-speed forming process that employs high-pressure shock wave in fluid. When the electric energy is discharged from a capacitor bank, it is transferred to the water through the electrode bar and it makes the fluid into a high-pressure plasma state. Due to the high-pressure water, the sheet can be deformed into the die shape. Because the numerical model of electrohydraulic forming deals with fluid and structural models at the same time, it needs coupling mechanism for parts. Therefore, in this study, numerical model for electrohydraulic forming was developed using the coupling of ALE (Arbitrary Lagrange-Eulerian) and lagrangian mesh. The fluid parts, plasma, vacuum and water, were modelled with ALE elements and structural parts, die, chamber and sheet metal were modelled with general lagrangian mesh. The results of the numerical simulation showed that the plasma and water parts expanded due to the input energy, and the sheet metal was deformed with a speed above 100 m/s due to the pressure wave of the fluid parts.