An experimental study of contact pressure distribution in panel stamping operations

This paper presents an analysis of the dynamic contact pressure distribution at the sheet metal-tooling interface in normal and defective panel stamping operations. Specifically, the stamping of a 1.27 × 20 × 15 cm rectangular aluminum alloy panel has been simulated using finite-element modeling methods. The modeling results are leveraged to determine the forces acting on sensors embedded in the die structure. Based on these results, a customized stamping test bed has been designed, which incorporates an array of force sensors embedded into the stamping die to enable online measurement of the forces in the die. The force measurements are processed by the thin plate spline numeric surface interpolation method to evaluate a continuous contact pressure distribution map of the die cavity. The pressure distribution in the die cavity in normal and defective scenarios has been presented along with a suggested volume thresholding method for automated defect detection. By leveraging the numeric surface generation method to analyze experimental data, the present study establishes the basis for intelligent tooling and in-process monitoring for improved observability in sheet metal stamping.