Detection of Punch Wear in Stamping Process Using Acoustic Emission

Stamping process is widely used for the production of sheet metal components because of its high productivity and accuracy. The performance of stamping depends on the condition of punch and die. Variation in punch and die dimension has a significant influence on the product quality. The purpose of the present study is to identify the state of punch wear. In this paper, acoustic emission (AE) signals from the process utilized to identify the three different punch wear conditions. The recorded acoustic signals after filtering were processed using Hilbert–Huang Transform (HHT). Then, the instantaneous frequencies and amplitudes were obtained for the signal components. The Intrinsic Mode Functions (IMF) of the AE for the three punch condition were analyzed. With the increase in punch wear, the instantaneous amplitude of the signal increases while instantaneous frequency remains unaffected.