The goal of this study was to verify, experimentally and numerically, that the stamp hydroforming process is a suitable alternative to conventional stamping as a means for producing defect-free sheet metal parts. The pressurized fluid used in stamp hydroforming is shown to have the effect of increasing the forming limits of materials; that is deeper drawing depths are achieved without rupture. Also, using a specific pressure profile, wrinkle-free parts with deeper draws could be produced. Stamp hydroforming involves supporting the sheet metal with a bed of pressurized viscous fluid during the entire forming process. The external support provides a through-thickness compressive stress that delays the onset of tearing and wrinkling. Stamp hydroforming experiments with a hemispherical punch were conducted using the Interlaken double-action stamping press. Numerical analysis was conducted using the explicit finite element code LS-Dyna3D. The accuracy of the numerical model was first established and fine-tuned using experimental data. The numerical model was then used to explore new forming ideas not currently possible with the present experimental setup. A new blank holder design is suggested from these numerical results.
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