Potential drop in the center-cracked panel with asymmetric crack extension

✍ Scribed by D. T. Read; M. Pfuff

• Publisher: Springer Netherlands
• Year: 1991
• Tongue: English
• Weight: 462 KB
• Volume: 48
• Category: Article
• ISSN: 1573-2673
• DOI: 10.1007/bf00036633

✦ Synopsis

The well-known Johnson formula relates the electrical potential drop across a symmetric center crack in a current-carrying tensile panel to the crack length. To allow individual measurement of the crack growth at both ends of such a crack, the potential measured between contact points located on opposite sides and equidistant from the panel center line has been studied . Because this potential must ideally be identically zero for symmetric crack growth, it is termed the asymmetric potential . Its sign and magnitude are related to the direction and extent of asymmetric crack growth .

It was found that contact points directly above the ends of the initial symmetric crack provide a signal which is well-suited to the determination of the asymmetry of the crack extension . This information is complementary to the total crack length information obtained using the Johnson formula . Experimental measurements and theoretical results were used to produce calibration formulae relating the asymmetric potential to the asymmetry of the crack dimensions in center-cracked panels .