Dynamical impact of liquid pressure impulses and vibrations in the hydro-formation process

Résumé

The work relates the impact of the dynamical action of the pressure impulses and vibrations, through the hydraulic medium, to the sheet billet in the plastic deformation process through hydro-formation. The theoretical pressures and forces estimated are deducted and posted, with and without pressure pulses and vibrations and the influence of the specific resonance frequency on the sheet billet. The paper presents also the experimental results regarding the possibility to convey the pressure pulses and vibrations through the hydro-formation liquid, the theoretical and experimental influence of liquid viscosity and compressibility beside the process and the theoretical and experimental method used to determine in dynamics the resonance frequency of the sheet billet in the period of changing forms due to hydroformation action.