Title :
Ultrasonic instrument to predict drawability of sheet metal
Author :
Papadakis, E.P. ; Thompson, R.B. ; Bluhm, D.D. ; Wormley, S.J. ; Skank, H.D. ; Forouraghi, K. ; Alers, G.A.
Author_Institution :
Iowa State Univ., Ames, IA, USA
Abstract :
An ultrasonic instrument has been designed and fabricated to predict drawability of sheet metal. Using S0 mode Lamb waves generated and detected by EMATs (electromagnetic-acoustic transducers), the instrument automatically measures ultrasonic phase delay in three directions: 0°, 45°, and 90° with respect to the rolling direction. The delay is measured by a Fourier transform phase-versus-frequency slope algorithm applied to flash AD recorded EMAT signals. From the delays, the computer-based instrument calculates velocities and the directional Young´s modulus E(O) in the rolling plane. From the average E in the plane, a correlation curve is used to find the average plastic strain ratio, which is the drawability prediction parameter
Keywords :
Young´s modulus; drawing (mechanical); ductility; metals; ultrasonic materials testing; Fourier transform phase-versus-frequency slope algorithm; Lamb waves; average plastic strain ratio; computer-based instrument; correlation curve; directional Young´s modulus; drawability prediction parameter; electromagnetic-acoustic transducers; rolling direction; rolling plane; sheet metal; ultrasonic instrument; ultrasonic phase delay; Capacitive sensors; Electromagnetic measurements; Fourier transforms; Instruments; Phase detection; Phase measurement; Plastics; Propagation delay; Ultrasonic transducers; Ultrasonic variables measurement;
Conference_Titel :
Ultrasonics Symposium, 1990. Proceedings., IEEE 1990
Conference_Location :
Honolulu, HI
DOI :
10.1109/ULTSYM.1990.171514
