NUMERICAL SIMULATION ON MANUFACTURING OF PRESSURE VESSEL FOR SHOCK FOOD PROCESSING USING EXPLOSIVE FORMING

The explosive forming is a characteristic forming method. An underwater shock wave is generated by underwater explosion of the explosive. A metal plate is affected high strain rate by the shock loading and is formed along a metal die. Although this method has the advantage of mirroring the shape of the die, a free forming was used in this paper. An expensive metal die is not necessary for this free forming. It is possible that a metal plate is formed with simple supporting parts. However, the forming shape is depend on the shock pressure distribution act on the metal plate. This pressure distribution is able to change by the shape of explosive, a mass of explosive and a shape of pressure vessel. On the other hand, we need the pressure vessel for food processing by the underwater shock wave. Therefore, we propose making the pressure vessel by the explosive forming. One design suggestion of pressure vessel made of stainless steel was considered. However, we cannot decide suitable conditions, the mass of the explosive and the distance between the explosive and the metal plate to make the pressure vessel. In order to decide these conditions, we have tried the numerical simulation of this explosive forming. The basic simulation method was ALE (Arbitrary Laglangian Eulerian) method. Mie-Griimeisen EOS (equation of state), JWL EOS, Johnson-Cook constitutive equation for a material model were applied in the numerical simulation. In this paper, the underwater pressure contours to clear the propagations of the underwater shock wave, forming processes and deformation velocity of the metal plate is shown and it will be discussed about those results.