Volume 3, Issue 4 (July 1975)
A New Method of Detecting Fatigue Crack Propagation in Ferromagnetic Specimens
This paper describes a new method for detecting fatigue crack growth in ferromagnetic specimens. This method is similar to the Barkhausen effect type of measurement, where discontinuous voltage pulses are induced in a pickup coil surrounding a specimen when the specimen is magnetized slowly. As a fatigue crack grows, similar voltage pulses are generated. Simultaneous display of the Barkhausen-type magnetic signals and the acoustic emission signals during fatigue crack propagation show that they are correlated.