Author(s)

P.C.H. Ament, A.H.M. Krom & M. Janssen

Abstract

The potential drop technique is a powerful method to monitor the crack length in fatigue research. The DC potential drop method relies on the fact that a constant DC current is passed through the test specimen in such a way that a change in crack length alters the potential difference of suitably placed potential probe points. The technique is simple, robust, highly stable and suitable for automation. Disadvantages of the technique are: a calibration curve is necessary (simple experimental or complex numerical calibrations), if crack faces short an underestimation of the crack length is obtained, thermal electromotive forces can cause problems and high DC currents can cause heating

Keywords